JP7044494B2 - Method for producing salt, resist composition and resist pattern - Google Patents

Description

The present invention relates to a method for producing a salt, a resist composition and a resist pattern used for microfabrication of a semiconductor.

特許文献２には、酸発生剤用の塩として、下記式で表される塩を含有するレジスト組成物が記載されている。

Patent Document 1 describes a resist composition containing a salt represented by the following formula as a salt for an acid generator.

Patent Document 2 describes a resist composition containing a salt represented by the following formula as a salt for an acid generator.

Japanese Unexamined Patent Publication No. 2011-081044 Japanese Unexamined Patent Publication No. 2014-199389

In the resist composition containing the salt represented by the above formula, the mask error factor (MEF) may not always be satisfactory.

［式（Ｉ）中、
Ｘは、酸素原子、硫黄原子又は－Ｎ（ＳＯ_２Ｒ^５）－を表す。
Ｒ^５は、フッ素原子を有してもよい炭素数１～１２のアルキル基、フッ素原子を有してもよい炭素数３～１２の脂環式炭化水素基又はフッ素原子を有してもよい炭素数６～１２の芳香族炭化水素基を表し、該アルキル基又は該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。
Ａｒは、置換基を有していてもよい炭素数６～３６の２価の芳香族炭化水素基又は置換基を有していてもよい炭素数４～３６の２価のヘテロ芳香族炭化水素基を表す。
Ｒ^１及びＲ^２は、それぞれ独立に、水素原子、ヒドロキシ基又は炭素数１～１２の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。
ｍ及びｎは、それぞれ独立に、１又は２を表す。ｍが２のとき、２つのＲ^１は同一又は相異なり、ｎが２のとき、２つのＲ^２は同一又は相異なる。
Ｘ^１は、＊－Ｏ－、＊－Ｏ－ＣＯ－、＊－ＣＯ－Ｏ－、＊－Ｏ－ＣＯ－Ｏ－又は＊－Ｏ－ＣＨ_２－ＣＯ－Ｏ－を表す。＊はＡｒとの結合位を表す。
Ｗは、炭素数３～３６の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれるメチレン基は、酸素原子、硫黄原子、カルボニル基又はスルホニル基で置換されていてもよく、該脂環式炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基、炭素数１～１２のアルキル基、炭素数１～１２のアルコキシ基、炭素数３～１２の脂環式炭化水素基、炭素数６～１０の芳香族炭化水素基又はこれらを組み合わせた基で置換されていてもよい。
Ａ^－は、有機アニオンを表す。］
［２］Ｘ^１は、＊－Ｏ－ＣＯ－（＊はＡｒとの結合位を表す。）である［１］に記載の塩。
［３］Ｗは、シクロヘキシル基、ノルボルニル基又はアダマンチル基であり、該シクロヘキシル基、ノルボルニル基又はアダマンチル基に含まれるメチレン基は、酸素原子、硫黄原子、カルボニル基又はスルホニル基で置換されていてもよく、該シクロヘキシル基、ノルボルニル基又はアダマンチル基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基、炭素数１～１２のアルキル基、炭素数１～１２のアルコキシ基、炭素数３～１２の脂環式炭化水素基、炭素数６～１０の芳香族炭化水素基又はこれらを組み合わせた基で置換されていてもよい［１］又は［２］記載の塩。
［４］Ａｒは、フェニレン基である［１］～［３］のいずれかに記載の塩。
［５］有機アニオンが、有機スルホン酸アニオンである［１］～［４］のいずれかに記載の塩。
［６］有機アニオンが、式（Ｉ－Ａ）で表されるアニオンである［１］～［４］のいずれかに記載の塩。

［式（Ｉ－Ａ）中、
Ｑ¹及びＱ²は、それぞれ独立して、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１～２４の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよいメチル基又は置換基を有していてもよい炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。］
［７］Ｙが、置換基を有していてもよいアダマンチル基を表し、該アダマンチル基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい［６］記載の塩。
［８］［１］～［７］のいずれかに記載の塩と酸不安定基を有する樹脂とを含有するレジスト組成物。
［９］酸不安定基を有する樹脂が、さらに、ラクトン環を有する構造単位を含む［８］記載のレジスト組成物。
［１０］酸発生剤から発生する酸よりも酸性度の弱い酸を発生する塩をさらに含有する［８］又は［９］記載のレジスト組成物。
［１１］さらに、フッ素原子を有する構造単位を含む樹脂を含有する［８］～［１０］のいずれかに記載のレジスト組成物。
［１２］（１）［８］～［１１］のいずれかに記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層に露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A salt represented by the formula (I).

[In formula (I),
X represents an oxygen atom, a sulfur atom or -N (SO ₂ R ⁵ )-.
R ⁵ may have an alkyl group having 1 to 12 carbon atoms which may have a fluorine atom, an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a fluorine atom, or a fluorine atom. Representing an aromatic hydrocarbon group having 6 to 12 carbon atoms, -CH _2- contained in the alkyl group or the alicyclic hydrocarbon group may be replaced with -O- or -CO-.
Ar is a divalent aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent or a divalent heteroaromatic hydrocarbon having 4 to 36 carbon atoms which may have a substituent. Represents a group.
R ¹ and R ² independently represent a hydrogen atom, a hydroxy group, or a hydrocarbon group having 1 to 12 carbon atoms, and -CH _2- contained in the hydrocarbon group is -O- or -CO-. It may be replaced.
m and n independently represent 1 or 2, respectively. When m is 2, the two ^R1s are the same or different, and when n is 2, the ^two R2s are the same or different.
X ¹ represents * -O-, * -O-CO-, * -CO-O-, * -O-CO-O- or * -O-CH ₂ -CO-O-. * Represents the bond position with Ar.
W represents an alicyclic hydrocarbon group having 3 to 36 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the alicyclic hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an alicyclic hydrocarbon having 3 to 12 carbon atoms. It may be substituted with a group, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a group in which these are combined.
A ^- represents an organic anion. ]
[2] The salt according to [1], wherein X ¹ is * -O-CO- (* represents a bond with Ar).
[3] W is a cyclohexyl group, a norbornyl group or an adamantyl group, and the methylene group contained in the cyclohexyl group, norbornyl group or adamantyl group may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. Often, the hydrogen atom contained in the cyclohexyl group, norbornyl group or adamantyl group is a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an alicyclic group having 3 to 12 carbon atoms. The salt according to [1] or [2], which may be substituted with a hydrocarbon group of the formula, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a group in which these are combined.
[4] Ar is the salt according to any one of [1] to [3], which is a phenylene group.
[5] The salt according to any one of [1] to [4], wherein the organic anion is an organic sulfonic acid anion.
[6] The salt according to any one of [1] to [4], wherein the organic anion is an anion represented by the formula (IA).

[In formula (IA),
Q ¹ and Q ² independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-, and the saturated hydrocarbon group may be replaced. The hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and is contained in the alicyclic hydrocarbon group. CH _2- may be replaced with -O-, -SO _2- or -CO-. ]
[7] The description of [6], wherein Y represents an adamantyl group which may have a substituent, and -CH _2- contained in the adamantyl group may be replaced with -O- or -CO-. salt.
[8] A resist composition containing the salt according to any one of [1] to [7] and a resin having an acid unstable group.
[9] The resist composition according to [8], wherein the resin having an acid unstable group further contains a structural unit having a lactone ring.
[10] The resist composition according to [8] or [9], which further contains a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.
[11] The resist composition according to any one of [8] to [10], further containing a resin containing a structural unit having a fluorine atom.
[12] (1) A step of applying the resist composition according to any one of [8] to [11] onto a substrate.
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
(4) A method for producing a resist pattern, which comprises a step of heating the composition layer after exposure and (5) a step of developing the composition layer after heating.

Provided are a salt capable of producing a resist pattern with a good mask error factor (MEF) and a resist composition containing the salt.

In the present specification, unless otherwise specified, a hydrocarbon group having both a linear structure and a branched structure such as "aliphatic hydrocarbon group" in the description of the structural formula of a compound includes both of them. The "aliphatic hydrocarbon group" means a group obtained by removing a number of hydrogen atoms corresponding to a valence from the ring of an alicyclic hydrocarbon. The "aromatic hydrocarbon group" also includes a group in which a hydrocarbon group is bonded to an aromatic ring. If a steric isomer is present, it includes all steric isomers.
The "(meth) acrylic monomer" means at least one kind of monomer having a structure of "CH ₂ = CH-CO-" or "CH ₂ = C (CH ₃ ) -CO-". Similarly, "(meth) acrylate" and "(meth) acrylic acid" mean "at least one of acrylate and methacrylate" and "at least one of acrylic acid and methacrylic acid", respectively.
In the present specification, the "solid content of the resist composition" means the total amount of the components excluding the solvent (E) described later from the total amount of the resist composition.

［式（Ｉ）中、
Ｘは、酸素原子、硫黄原子又は－Ｎ（ＳＯ_２Ｒ^５）－を表す。
Ｒ^５は、フッ素原子を有してもよい炭素数１～１２のアルキル基、フッ素原子を有してもよい炭素数３～１２の脂環式炭化水素基又はフッ素原子を有してもよい炭素数６～１２の芳香族炭化水素基を表し、該アルキル基又は該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。
Ａｒは、置換基を有していてもよい炭素数４～３６の２価の芳香族炭化水素基又は置換基を有していてもよい炭素数４～３６の２価のヘテロ芳香族炭化水素基を表す。
Ｒ^１及びＲ^２は、それぞれ独立に、水素原子、ヒドロキシ基又は炭素数１～１２の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。
ｍ及びｎは、それぞれ独立に、１又は２を表す。ｍが２のとき、２つのＲ^１は同一又は相異なり、ｎが２のとき、２つのＲ^２は同一又は相異なる。
Ｘ^１は、＊－Ｏ－、＊－Ｏ－ＣＯ－、＊－ＣＯ－Ｏ－、＊－Ｏ－ＣＯ－Ｏ－又は＊－Ｏ－ＣＨ_２－ＣＯ－Ｏ－を表す。＊はＡｒとの結合位を表す。
Ｗは、炭素数３～３６の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれるメチレン基は、酸素原子、硫黄原子、カルボニル基又はスルホニル基で置換されていてもよく、該脂環式炭化水素基に含まれる水素原子は、ヒドロキシ基、炭素数１～１２のアルキル基、炭素数１～１２のアルコキシ基、炭素数３～１２の脂環式炭化水素基、炭素数６～１０の芳香族炭化水素基又はこれらを組み合わせた基で置換されていてもよい。
Ａ^－は、有機アニオンを表す。］ <Salt represented by the formula (I) (hereinafter, may be referred to as salt (I))>

[In formula (I),
X represents an oxygen atom, a sulfur atom or -N (SO ₂ R ⁵ )-.
R ⁵ may have an alkyl group having 1 to 12 carbon atoms which may have a fluorine atom, an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a fluorine atom, or a fluorine atom. Representing an aromatic hydrocarbon group having 6 to 12 carbon atoms, -CH _2- contained in the alkyl group or the alicyclic hydrocarbon group may be replaced with -O- or -CO-.
Ar is a divalent aromatic hydrocarbon group having 4 to 36 carbon atoms which may have a substituent or a divalent heteroaromatic hydrocarbon having 4 to 36 carbon atoms which may have a substituent. Represents a group.
R ¹ and R ² each independently represent a hydrogen atom, a hydroxy group, or a hydrocarbon group having 1 to 12 carbon atoms, and -CH _2- contained in the hydrocarbon group is -O- or -CO-. It may be replaced.
m and n independently represent 1 or 2, respectively. When m is 2, the two ^R1s are the same or different, and when n is 2, the ^two R2s are the same or different.
X ¹ represents * -O-, * -O-CO-, * -CO-O-, * -O-CO-O- or * -O-CH ₂ -CO-O-. * Represents the bond position with Ar.
W represents an alicyclic hydrocarbon group having 3 to 36 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the alicyclic hydrocarbon group is a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and carbon. It may be substituted with an aromatic hydrocarbon group having a number of 6 to 10 or a group combining these groups.
A ^- represents an organic anion. ]

Examples of the divalent aromatic hydrocarbon group represented by Ar include a phenylene group, a naphthylene group, an anthrasenylene group, a phenanthonylene group, a trilen group, a xylylene group, a dimethylphenylene group, a trimethylphenylene group, an ethylphenylene group and a propylphenylene group. Examples thereof include a group, a butylphenylene group, a biphenylene group, a triphenylene group, an indenylene group and a tetrahydronaphthylene group. The divalent aromatic hydrocarbon group represented by Ar preferably has 6 to 24 carbon atoms, and more preferably 6 to 18 carbon atoms.
Examples of the hetero atom include a nitrogen atom, an oxygen atom and a sulfur atom.
Examples of the divalent heteroaromatic hydrocarbon group include a furylene group and a thienylene group, preferably having 4 to 24 carbon atoms, and more preferably 4 to 18 carbon atoms.
Ar is preferably a divalent aromatic hydrocarbon group, more preferably a phenylene group.
Substituents of the divalent aromatic hydrocarbon group represented by Ar and the divalent heteroaromatic hydrocarbon group include a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, and an alkylcarbonyloxy having 2 to 18 carbon atoms. Examples include a group, an arylcarbonyloxy group having 7 to 18 carbon atoms or an alkoxycarbonyloxy group having 2 to 18 carbon atoms, and -CH _2- contained in the alkoxy group having 1 to 12 carbon atoms is replaced with -O-. May be. The substituent of the aromatic hydrocarbon group represented by Ar and the heteroaromatic hydrocarbon group is preferably a hydroxy group.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group. It is preferably an alkoxy group having 1 to 6 carbon atoms, and more preferably a methoxy group.
Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, and a tert-butylcarbonyloxy group. Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group and a 2-ethylhexylcarbonyloxy group. It is preferably an alkylcarbonyloxy group having 2 to 12 carbon atoms, and more preferably a methylcarbonyloxy group.
Examples of the arylcarbonyloxy group include a phenylcarbonyloxy group and a tosylcarbonyloxy group. It is preferably an arylcarbonyloxy group having 7 to 12 carbon atoms, and more preferably a phenylcarbonyloxy group.
Examples of the alkoxycarbonyloxy group include methoxycarbonyloxy group, ethoxycarbonyloxy group, n-propoxycarbonyloxy group, isopropoxycarbonyloxy group, n-butoxycarbonyloxy group, sec-butoxycarbonyloxy group and tert-butoxycarbonyloxy group. , Pentyloxycarbonyloxy group, hexyloxycarbonyloxy group, octyloxycarbonyloxy group and 2-ethylhexyloxycarbonyloxy group. It is preferably an alkyloxycarbonyloxy group having 2 to 8 carbon atoms, and more preferably a tert-butyloxycarbonyloxy group.

Examples of the hydrocarbon group represented by R ¹ and R ² include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by a combination thereof.
Alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group and octyl group. , Nonyl group, decyl group, undecyl group, dodecyl group and the like.
The alicyclic hydrocarbon group may be either a monocyclic group or a polycyclic group, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and a methylcyclohexyl group. , Cycloalkyl groups such as dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, and a norbornyl group. Examples thereof include a methylnorbornyl group and an isobornyl group.
Examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group.
Examples of the group formed by the combination include an aralkyl group, and a benzyl group and a phenethyl group.
The group in which -CH _2- contained in the hydrocarbon group is replaced with -O- or -CO- is a methoxy group, an ethoxy group, a butoxy group, an acetyl group, a methoxycarbonyl group, an acetyloxy group, or a butoxycarbonyloxy group. And benzoyloxy groups.

Alkyl groups having 1 to ¹² carbon atoms represented by R5 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl. Examples thereof include a group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group and a dodecyl group.
Examples of the alkyl group having 1 to ¹² carbon atoms having a fluorine atom represented by R5 include a trifluoromethyl group, a difluoromethyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, and 1,1,2. , 2-Tetrafluoroethyl group, Perfluoropropyl group, 1,1,1,2,2-Pentafluoropropyl group, Perfluorobutyl group, 1,1,2,2,3,3,4,4-Octafluorobutyl Examples include a group, a perfluoropentyl group, a 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, an n-perfluorohexyl group and the like.
The alicyclic hydrocarbon group having ³ to 12 carbon atoms represented by R5 may be either a monocyclic or polycyclic group, and the monocyclic alicyclic hydrocarbon group may be a cyclopropyl group or the like. Cycloalkyl groups such as cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group and cyclodecyl group can be mentioned. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, and a norbornyl group. Examples thereof include a methylnorbornyl group and an isobornyl group.
Examples of the aromatic hydrocarbon group having ⁶ to 12 carbon atoms represented by R5 include a phenyl group and a naphthyl group.

The alicyclic hydrocarbon group represented by W may be either a monocyclic or polycyclic ring, or may be a spiro ring. When the methylene group contained in the alicyclic hydrocarbon group is replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group, the number of replaced _−CH2- may be one, or two or more, three or more, four or more, and the like. There may be more than one. In this case, the methylene group contained in the alicyclic hydrocarbon group is preferably substituted with an oxygen atom, a sulfur atom, a carbonyloxy group or a sulfonyl group, and more preferably substituted with a carbonyloxy or a sulfonyl group.
Examples of the alicyclic hydrocarbon group include groups represented by the formulas (W1) to (W38).

Ring W has a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and an aromatic hydrocarbon having 6 to 10 carbon atoms. It may be substituted with a hydrogen group or a group in which these are combined.
Examples of the alkyl group, the alkoxy group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, or a group combining these groups are the same as those described above.
Of these, a hydroxy group, a hydroxyalkyl group or an alkoxy group is preferable, and a hydroxy group or a hydroxyalkyl group is preferable.

m is preferably 2.
n is preferably 2.
It is preferable that at least one of m and n is 2, and it is more preferable that both m and n are 2.
R ¹ and R ² are preferably the same group.
R ¹ is preferably a hydrogen atom.
R ² is preferably a hydrogen atom.
R ³ is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
^R4 is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
It is preferable that either R ³ or R ⁴ is a hydrogen atom, and it is more preferable that both are hydrogen atoms.
Ar is preferably an aromatic hydrocarbon group having 6 to 36 carbon atoms, more preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms, further preferably a phenylene group, a tolylen group, a xylylene group, or a dimethylphenylene group, and a phenylene group. Is particularly preferable.
X is preferably a single bond, a methylene group or an oxygen atom, more preferably a single bond or a methylene group, and even more preferably a single bond.
X ¹ is preferably * -O-CO-, * -CO-O-, * -O-CO-O- or * -O-CH ₂ -CO-O-, preferably * -O-CO-. Alternatively, it is more preferably * -CO-O-, and further preferably * -O-CO- (* represents a binding position with Ar).
W is more preferably a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, an adamantyl group, or a norbornyl group, further preferably a cyclohexyl group, an adamantyl group, or a norbornyl group, and is preferably an adamantyl group. Even more preferable. Further, these are preferably those in which the hydroxy group or the hydroxyalkyl group is substituted, and more preferably those in which the hydroxy group is substituted.

Examples of the cation in the salt (I) (hereinafter, may be referred to as a cation (I)) include the following cations and the like. The cation (I) is represented by the formula (I-c-1), the formula (I-c-2), the formula (I-c-3), the formula (I-c-5), and the formula (I-c-7). , Formula (I-c-9), Formula (I-c-10), Formula (I-c-11), Formula (I-c-15), Formula (I-c-16) and Formula (I-). The cation represented by c-17) is preferable.

［式（Ｉ－Ａ）中、
Ｑ¹及びＱ²は、それぞれ独立して、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１～２４の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよいメチル基又は置換基を有していてもよい炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。］ A ⁻ represents a monovalent anion, and specifically, a halide ion, a hydroxide ion, an organic sulfonic acid anion, an organic sulfonylimide anion, an organic sulfonylmethide anion, an alkoxide anion, a phenoxide anion, a carboxylic acid anion and the like. Organic anion of.
A ⁻ is preferably a halide ion or an organic anion, more preferably an organic sulfonic acid anion or a carboxylic acid anion, and even more preferably an organic sulfonic acid anion.
The organic sulfonic acid anion is preferably an organic sulfonic acid anion having a sulfo group and a fluorine atom, and more preferably an anion represented by the formula (IA).

[In formula (IA),
Q ¹ and Q ² independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-, and the saturated hydrocarbon group may be replaced. The hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and is contained in the alicyclic hydrocarbon group. CH _2- may be replaced with -O-, -SO _2- or -CO-. ]

The perfluoroalkyl groups of ^Q1 and ^Q2 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and perfluoro. A hexyl group and the like can be mentioned.
^Q1 and ^Q2 are preferably fluorine atoms or trifluoromethyl groups independently of each other, and more preferably both are fluorine atoms.

Examples of the divalent saturated hydrocarbon group of L ^b1 include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. It may be a group formed by combining two or more kinds of groups.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 , 7-Diyl group, Octane-1,8-Diyl group, Nonan-1,9-Diyl group, Decan-1,10-Diyl group, Undecan-1,11-Diyl group, Dodecan-1,12-Diyl group , Tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group. Alcandiyl group;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, etc. Valuable alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbons such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group. The group etc. can be mentioned.

［式（ｂ１－１）中、
Ｌ^ｂ２は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ３は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ただし、Ｌ^ｂ２とＬ^ｂ３との炭素数合計は、２２以下である。
式（ｂ１－２）中、
Ｌ^ｂ４は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ５は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ただし、Ｌ^ｂ４とＬ^ｂ５との炭素数合計は、２２以下である。
式（ｂ１－３）中、
Ｌ^ｂ６は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
Ｌ^ｂ７は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ただし、Ｌ^ｂ６とＬ^ｂ７との炭素数合計は、２３以下である。］ Examples of the group in which -CH _2- in the divalent saturated hydrocarbon group of L ^b1 is replaced with -O- or -CO- are any of the formulas (b1-1) to (b1-3). The group represented by is mentioned. In the formulas (b1-1) to (b1-3) and the following specific examples, * represents a bond with −Y.

[In equation (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated hydrocarbon group may be substituted. The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total number of carbon atoms of L ^b2 and L ^b3 is 22 or less.
In equation (b1-2),
L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated hydrocarbon group may be substituted. The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total number of carbon atoms of L ^b4 and L ^b5 is 22 or less.
In equation (b1-3),
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated hydrocarbon group may be substituted. The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total number of carbon atoms of L ^b6 and L ^b7 is 23 or less. ]

In the formulas (b1-1) to (b1-3), when the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group, the number of carbon atoms before the replacement is the carbon of the saturated hydrocarbon group. Let it be a number.
Examples of the divalent saturated hydrocarbon group include those similar to the divalent saturated hydrocarbon group of L ^b1 .

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single-bonded or divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. The methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
The group in which _-CH2- in the divalent saturated hydrocarbon group of L ^b1 is replaced with -O- or -CO- is a group represented by the formula (b1-1) or the formula (b1-3). Is preferable.

［式（ｂ１－４）中、
Ｌ^ｂ８は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
式（ｂ１－５）中、
Ｌ^ｂ９は、炭素数１～２０の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｌ^ｂ１０は、単結合又は炭素数１～１９の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ９及びＬ^ｂ１０の合計炭素数は２０以下である。
式（ｂ１－６）中、
Ｌ^ｂ１１は、炭素数１～２１の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｌ^ｂ１２は、単結合又は炭素数１～２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１１及びＬ^ｂ１２の合計炭素数は２１以下である。
式（ｂ１－７）中、
Ｌ^ｂ１３は、炭素数１～１９の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｌ^ｂ１４は、単結合又は炭素数１～１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１５は、単結合又は炭素数１～１８の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１３～Ｌ^ｂ１５の合計炭素数は１９以下である。
式（ｂ１－８）中、
Ｌ^ｂ１６は、炭素数１～１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｌ^ｂ１７は、炭素数１～１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１８は、単結合又は炭素数１～１７の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１６～Ｌ^ｂ１８の合計炭素数は１９以下である。］ Examples of the formula (b1-1) include groups represented by the formulas (b1-4) to (b1-8).

[In equation (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
In equation (b1-5),
L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total carbon number of L ^b9 and L ^b10 is 20 or less.
In equation (b1-6),
L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total carbon number of L ^b11 and L ^b12 is 21 or less.
In equation (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total number of carbon atoms of L ^b13 to L ^b15 is 19 or less.
In equation (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total number of carbon atoms of L ^b16 to L ^b18 is 19 or less. ]

L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

［式（ｂ１－９）中、
Ｌ^ｂ１９は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２０は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子はフッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１９及びＬ^ｂ２０の合計炭素数は２３以下である。
式（ｂ１－１０）中、
Ｌ^ｂ２１は、単結合又は炭素数１～２１の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２２は、単結合又は炭素数１～２１の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｌ^ｂ２３は、単結合又は炭素数１～２１の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ２１～Ｌ^ｂ２３の合計炭素数は２１以下である。
式（ｂ１－１１）中、
Ｌ^ｂ２４は、単結合又は炭素数１～２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２５は、炭素数１～２１の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｌ^ｂ２６は、単結合又は炭素数１～２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ２４～Ｌ^ｂ２６の合計炭素数は２１以下である。］ Examples of the formula (b1-3) include groups represented by the formulas (b1-9) to (b1-11).

[In equation (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. May be good. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
However, the total carbon number of L ^b19 and L ^b20 is 23 or less.
In equation (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. May be. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
However, the total carbon number of L ^b21 to L ^b23 is 21 or less.
In equation (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. May be. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
However, the total carbon number of L ^b24 to L ^b26 is 21 or less. ]

In formulas (b1-9) to (b1-11), when the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with an acyloxy group, the number of carbon atoms of the acyloxy group, CO in the ester bond and The number of carbon atoms of the divalent saturated hydrocarbon group including the number of O is used.

Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, an adamantylcarbonyloxy group and the like.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-4) include the following.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-5) include the following.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-6) include the following.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-7) include the following.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-8) include the following.

Examples of the group represented by the formula (b1-2) include the following.

Among the groups represented by the formula (b1-3), the groups represented by the formula (b1-9) include the following.

Among the groups represented by the formula (b1-3), the groups represented by the formula (b1-10) include the following.

Among the groups represented by the formula (b1-3), the groups represented by the formula (b1-11) include the following.

Examples of the alicyclic hydrocarbon group represented by Y include groups represented by the formulas (Y1) to (Y11) and the formulas (Y36) to (Y38).
When -CH _2- contained in the alicyclic hydrocarbon group represented by Y is replaced by -O-, -SO _2- or -CO-, the number may be one or two or more. .. Examples of such a group include groups represented by the formulas (Y12) to (Y35).

Among them, it is preferably a group represented by any one of the formula (Y1) to the formula (Y20), the formula (Y30), and the formula (Y31), and more preferably the formula (Y11), the formula (Y15), and the formula (Y11). Y16), a group represented by the formula (Y20), the formula (Y30) or the formula (Y31), and more preferably a group represented by the formula (Y11), the formula (Y15) or the formula (Y30).
When Y constitutes a spiro ring of the formulas (Y28) to (Y33) and the like, the alkanediyl group between the two oxygens preferably has one or more fluorine atoms. Further, among the alkanediyl groups contained in the ketal structure, those in which the fluorine atom is not substituted in the methylene group adjacent to the oxygen atom are preferable.

The substituent of the alicyclic hydrocarbon group represented by Y includes an alkyl group having 1 to 12 carbon atoms and an alicyclic group having 3 to 16 carbon atoms which may be substituted with a halogen atom, a hydroxy group or a hydroxy group. Hydrocarbon groups, alkoxy groups with 1 to 12 carbon atoms, aromatic hydrocarbon groups with 6 to 18 carbon atoms, aralkyl groups with 7 to 21 carbon atoms, acyl groups with 2 to 4 carbon atoms, glycidyloxy groups or-(CH) ₂ ) _ja -O-CO-R ^b1 group (in the formula, R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic hydrocarbon having 6 to 18 carbon atoms. Represents a hydrogen group. Ja represents an integer of 0 to 4) and the like.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, an adamantyl group and the like.
Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group and a p-adamantylphenyl group; a trill group, a xylyl group, a cumenyl group and a mesityl group. , Biphenyl group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl and the like.
Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group and a heptyl group, 2 -Examples include ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group and the like.
Examples of the alkyl group substituted with the hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group.
Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group and a naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, a butyryl group and the like.

Examples of Y include the following.

When Y is a methyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated hydrocarbon group at the bond position with Y It is preferable that -CH _2- is replaced with -O- or -CO-.

Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably an adamantyl group which may have a substituent, and is said to be an alicyclic hydrocarbon. The methylene group constituting the hydrogen group or the adamantyl group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group. Y is more preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group or a group represented by the following.

The sulfonic acid anion in the salt represented by the formula (IA) is an anion represented by the formulas (B1-A-1) to (B1-A-55) [hereinafter, "anion" according to the formula number. (B1-A-1) ”and the like. ] Are preferable, and the formulas (B1-A-1) to (B1-A-4), formulas (B1-A-9), formulas (B1-A-10), and formulas (B1-A-24) to formulas (B1-A-24) to formulas are preferable. (B1-A-33), formula (B1-A-36) to formula (B1-A-40), formula (B1-A-47) to formula (B1-A-55). Anions are more preferred.

ここでＲ^ｉ２～Ｒ^ｉ７は、例えば、炭素数１～４のアルキル基、好ましくはメチル基又はエチル基である。Ｒ^ｉ８は、例えば、炭素数１～１２の脂肪族炭化水素基、好ましくは炭素数１～４のアルキル基、炭素数５～１２の脂環式炭化水素基又はこれらを組合せることにより形成される基、より好ましくはメチル基、エチル基、シクロヘキシル基又はアダマンチル基である。Ｌ^４は、単結合又は炭素数１～４のアルカンジイル基である。
Ｑ^１及びＱ^２は、上記と同じである。
式（Ｉ－Ａ）で表される塩におけるスルホン酸アニオンとしては、具体的には、特開２０１０－２０４６４６号公報に記載されたアニオンが挙げられる。

Here, R ⁱ² to R ⁱ⁷ are, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R ⁱ⁸ is formed, for example, by an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. Group, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L4 is a single bond or an alkanediyl group having 1 to ⁴ carbon atoms.
^Q1 and ^Q2 are the same as above.
Specific examples of the sulfonic acid anion in the salt represented by the formula (IA) include the anions described in JP-A-2010-204646.

Examples of the sulfonic acid anion in the salt (I) include anions represented by the formulas (B1a-1) to (B1a-34).

Examples of the organic sulfonylimide anion include the following.

As A ⁻ , the formulas (B1a-1) to (B1a-3), the formulas (B1a-7) to the formulas (B1a-16), the formulas (B1a-18), the formulas (B1a-19), and the formulas (B1a) An anion represented by any of -22) to the formula (B1a-34) is preferable.

Examples of the salt (I) include the salts shown in Table 1. In Table 1, the salt (I-1) is, for example, the salt shown below.

Examples of the salt (I) include salt (I-1), salt (I-2), salt (I-3), salt (I-12), salt (I-13), salt (I-14), and salt. (I-15), salt (I-16), salt (I-17), salt (I-18), salt (I-19), salt (I-28), salt (I-29), salt ( I-30), salt (I-31), salt (I-32), salt (I-129), salt (I-130), salt (I-131), salt (I-140), salt (I) -141), salt (I-142), salt (I-143), salt (I-144), salt (I-145), salt (I-146), salt (I-147), salt (I- 156), salt (I-157), salt (I-158), salt (I-159), salt (I-160), salt (I-161), salt (I-162), salt (I-163) ), Salt (I-172), salt (I-173), salt (I-174), salt (I-175) and salt (I-176) are preferred.

（式中、Ｒ^１、Ｒ^２、Ａｒ、Ｘ^１、Ｗ、Ｘ及びＡ^－は、前記と同義である。）
触媒としては、安息香酸銅（ＩＩ）等が挙げられる。
溶剤としては、モノクロロベンゼン等が挙げられる。 The salt (I) can be produced by reacting a salt represented by the formula (Ia) with a compound represented by the formula (Ib) in a solvent in the presence of a catalyst.

(In the formula, R ¹ , R ² , Ar, X ¹ , W, X and A ⁻ have the same meanings as described above.)
Examples of the catalyst include copper benzoate (II) and the like.
Examples of the solvent include monochlorobenzene and the like.

式（Ｉ－ａ）で表される塩は、例えば、式（Ｉ－ｃ）で表される塩と式（Ｉ－ｄ）で表される塩とを、溶剤中で反応させることにより製造することができる。

（式中、Ｘは塩素原子又は臭素原子を表す。）
溶剤としては、クロロホルム、水等が挙げられる。
式（Ｉ－ｄ）で表される化合物は、下記式で表される化合物等が挙げられる。

Examples of the salt represented by the formula (Ib) include compounds represented by the following formula.

The salt represented by the formula (Ia) is produced, for example, by reacting a salt represented by the formula (Ic) with a salt represented by the formula (Id) in a solvent. be able to.

(In the formula, X represents a chlorine atom or a bromine atom.)
Examples of the solvent include chloroform, water and the like.
Examples of the compound represented by the formula (Id) include compounds represented by the following formula.

塩基としては、Ｎ－メチルピロリジン、ピリジン等が挙げられる。
溶剤としては、アセトニトリル、クロロホルム等が挙げられる。
式（Ｉ１－ｅ）で表される化合物は、下記式で表される化合物等が挙げられる。

式（Ｉ１－ｆ）で表される塩は、下記式で表される塩等が挙げられる。

The salt represented by the formula (I1-c) in which X ¹ is * -O-CO- (* represents the binding position with Ar) is the compound represented by the formula (I1-e) and the formula. It can be produced by reacting the salt represented by (I1-f) in a solvent in the presence of a base catalyst.

Examples of the base include N-methylpyrrolidin, pyridine and the like.
Examples of the solvent include acetonitrile, chloroform and the like.
Examples of the compound represented by the formula (I1-e) include compounds represented by the following formula.

Examples of the salt represented by the formula (I1-f) include salts represented by the following formula.

溶剤としては、アセトニトリル、クロロホルム等が挙げられる。
式（Ｉ２－ｅ）で表される化合物は、

式（Ｉ２－ｆ）で表される化合物は、下記式で表される化合物等が挙げられる。

The salt represented by the formula (I2-c) in which X ¹ is * -CO-O- (* represents the bonding position with Ar) is the salt represented by the formula (I2-f) and the carbonyl. It can be produced by reacting imidazole with a solvent and then further reacting with a compound represented by the formula (I2-e).

Examples of the solvent include acetonitrile, chloroform and the like.
The compound represented by the formula (I2-e) is

Examples of the compound represented by the formula (I2-f) include compounds represented by the following formula.

溶剤としては、アセトニトリル、クロロホルム等が挙げられる。 The salt represented by the formula (I3-c) in which X ¹ is * -O-CO-O- (* represents the binding position with Ar) is a compound represented by the formula (I2-e). It can be produced by reacting carbonyldiimidazole with carbonyldiimidazole in a solvent and then further reacting with a salt represented by the formula (I1-f).

Examples of the solvent include acetonitrile, chloroform and the like.

塩基としては、水酸化カリウム等が挙げられる。
溶剤としては、アセトニトリル、クロロホルム等が挙げられる。 The salt represented by the formula (I4-c) in which X ¹ is * -O- (* represents the binding position with Ar) is the compound represented by the formula (I2-e) and the formula (I1). It can be produced by reacting the salt represented by −f) in a solvent in the presence of a base catalyst.

Examples of the base include potassium hydroxide and the like.
Examples of the solvent include acetonitrile, chloroform and the like.

塩基としては、Ｎ－メチルピロリジン、ピリジン等が挙げられる。
溶剤としては、アセトニトリル、クロロホルム等が挙げられる。
式（Ｉ５－ｅ）で表される化合物は、下記式で表される化合物等が挙げられる。

The salt represented by the formula (I5-c) in which X ¹ is * -O-CH ₂ -CO-O- (* represents the binding position with Ar) is represented by the formula (I5-e). It can be produced by reacting the compound to be used with a salt represented by the formula (I1-f) in a solvent in the presence of a base catalyst.

Examples of the base include N-methylpyrrolidin, pyridine and the like.
Examples of the solvent include acetonitrile, chloroform and the like.
Examples of the compound represented by the formula (I5-e) include compounds represented by the following formula.

[Resist composition]
The resist composition of the present invention contains a resin having an acid unstable group (hereinafter, may be referred to as "resin (A)") and a salt (I). The salt (I) may contain two or more kinds, and the salt (I) acts as an acid generator in the resist composition.
The resist composition may contain an acid generator known in the resist field (hereinafter, may be referred to as "acid generator (B)"). The resist composition preferably contains a quencher (hereinafter, may be referred to as “quencher (C)”), and preferably contains a solvent (hereinafter, may be referred to as “solvent (D)”).

<Resin (A)>
The resin (A) has a structural unit having an acid unstable group (hereinafter, may be referred to as “structural unit (a1)”). It is preferable that the resin (A) further contains a structural unit other than the structural unit (a1). As the structural unit other than the structural unit (a1), a structural unit having no acid unstable group (hereinafter, may be referred to as “structural unit (s)”) and other structural units (hereinafter, “structural unit (t)””. In some cases) and structural units known in the art.

［式（１）中、Ｒ^a1～Ｒ^a3は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～２０の脂環式炭化水素基又はこれらを組み合わせた基を表すか、Ｒ^a1及びＲ^a2は互いに結合してそれらが結合する炭素原子とともに炭素数３～２０の２価の脂環式炭化水素基を形成する。
ｎａは、０又は１を表す。
＊は結合手を表す。］

［式（２）中、Ｒ^a1’及びＲ^a2’は、それぞれ独立に、水素原子又は炭素数１～１２の炭化水素基を表し、Ｒ^a3’は、炭素数１～２０の炭化水素基を表すか、Ｒ^a2’及びＲ^a3’は互いに結合してそれらが結合する炭素原子とともに炭素数３～２０の２価の複素環基を形成し、該炭化水素基及び該２価の複素環基に含まれるメチレン基は、酸素原子又は硫黄原子で置き換わってもよい。
Ｘは、酸素原子又は硫黄原子を表す。
＊は結合手を表す。］ <Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid unstable group (hereinafter, may be referred to as “monomer (a1)”). The "acid-unstable group" means a group having a leaving group, which is removed by contact with an acid to form a hydrophilic group (eg, a hydroxy group or a carboxy group).
In the resin (A), the acid unstable group contained in the structural unit (a1) is preferably a group represented by the following formula (1) and / or a group represented by the formula (2).

[In the formula (1), R ^a1 to R ^a3 independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group combining these groups, or R. ^a1 and R ^a2 are bonded to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.
na represents 0 or 1.
* Represents a bond. ]

[In the formula (2), R ^a1'and R ^a2' each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^a3' represents a hydrocarbon group having 1 to 20 carbon atoms. Represented, R ^a2'and R ^a3' are bonded to each other to form a divalent heterocyclic group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded, and the hydrocarbon group and the divalent heterocyclic group are formed. The methylene group contained in the above may be replaced with an oxygen atom or a sulfur atom.
X represents an oxygen atom or a sulfur atom.
* Represents a bond. ]

アルキル基と脂環式炭化水素基とを組み合わせた基としては、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基、シクロヘキシルメチル基、アダマンチルメチル基、アダマンチルジメチル基、ノルボルニルエチル基等が挙げられる。
ｎａは、好ましくは０である。 Examples of the alkyl group of R ^a1 to R ^a3 include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group and the like.
The alicyclic hydrocarbon groups of R ^a1 to R ^a3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups (* indicates a bond). The alicyclic hydrocarbon group of R ^a1 to R ^a3 has preferably 3 to 16 carbon atoms.

Groups that combine an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, and a norbornylethyl group. And so on.
na is preferably 0.

Examples of -C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R a ² are bonded to each other to form a divalent alicyclic hydrocarbon group include the following groups. The divalent alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (a group in which R ^a1 to R ^a3 are alkyl groups in the formula (1), preferably a tert-butoxycarbonyl group) and 2-. Alkyl adamantan-2-yloxycarbonyl group (in formula (1), R ^a1 , R ^a2 and the carbon atom to which they are bonded form an adamantyl group and R ^a3 is an alkyl group) and 1- (adamantan-). 1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups and R ^a3 is an adamantyl group) and the like.

Ｒ^a1'及びＲ^a2'のうち、少なくとも１つは水素原子であることが好ましい。 Examples of the hydrocarbon group of R a1'to R ^{a3' include} an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same as above.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group and biphenyl. Examples thereof include an aryl group such as a group, a phenanthryl group, a 2,6-diethylphenyl group and a 2-methyl-6-ethylphenyl group.
Examples of the divalent heterocyclic group formed by R ^a2'and R ^a3'bonding to each other together with the carbon atom and X to which they are bonded include the following groups. * Represents a bond.

Of R ^a1'and R ^a2' , at least one is preferably a hydrogen atom.

Specific examples of the group represented by the formula (2) include the following groups. * Represents a bond.

The monomer (a1) is preferably a monomer having an acid unstable group and an ethylenically unsaturated bond, and more preferably a (meth) acrylic monomer having an acid unstable group.

Among the (meth) acrylic monomers having an acid unstable group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. If the resin (A) having a structural unit derived from the monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

［式（ａ１－０）中、式（ａ１－１）及び式（ａ１－２）中、
Ｌ^a01、Ｌ^ａ１及びＬ^ａ２は、それぞれ独立に、－Ｏ－又は^＊－Ｏ－（ＣＨ_２）_ｋ１－ＣＯ－Ｏ－を表し、ｋ１は１～７のいずれかの整数を表し、＊は－ＣＯ－との結合手を表す。
Ｒ^a01、Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a02、Ｒ^a03及びＲ^a04は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組み合わせた基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組み合わせることにより形成される基を表す。
ｍ１は、０～１４のいずれかの整数を表す。
ｎ１は、０～１０のいずれかの整数を表す。
ｎ１’は、０～３のいずれかの整数を表す。］ As the structural unit derived from the (meth) acrylic monomer having a group represented by the formula (1), the structural unit represented by the formula (a1-0) is preferably represented by the formula (a1-1). Examples thereof include a structural unit or a structural unit represented by the formula (a1-2). These may be used alone or in combination of two or more. In the present specification, the structural unit represented by the formula (a1-0), the structural unit represented by the formula (a1-1), and the structural unit represented by the formula (a1-2) are each structural unit (a1). -0), structural unit (a1-1) and structural unit (a1-2).

[In the formula (a1-0), in the formula (a1-1) and the formula (a1-2),
^La01 , ^La1 and ^La2 independently represent -O- or ^* -O- (CH ₂ ) _k1 -CO-O-, k1 represents an integer of 1 to 7, and * represents an integer of 1 to 7. -Represents a bond with CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these groups.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining them.
m1 represents any integer from 0 to 14.
n1 represents any integer from 0 to 10.
n1'represents an integer of 0 to 3. ]

^La01 , La1 and ^La2 are preferably oxygen atoms or * -O- (CH ₂ ) _k01 -CO-O- (where ^k01 is preferably an integer of 1 to 4, more preferably. Is 1), more preferably an oxygen atom.
R ^a4 and R ^a5 are preferably methyl groups.
The alkyl groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 , the alicyclic hydrocarbon group and the group combining these are the same as the groups listed in R ^a1 to R ^a3 of the formula (1). The group is mentioned.
The alkyl group of R ^a02 , R ^a03 and R ^a04 preferably has 1 to 6 carbon atoms, and more preferably a methyl group or an ethyl group.
The number of carbon atoms of the alkyl group in R ^a6 and R ^a7 is preferably 1 to 6, more preferably a methyl group, an ethyl group or an isopropyl group, and further preferably an ethyl group or an isopropyl group.
The ^alicyclic hydrocarbon groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R a 7 have preferably 5 to 12 carbon atoms, more preferably 5 to 10 carbon atoms.
The group in which the alkyl group and the alicyclic hydrocarbon group are combined preferably has a total carbon number of 18 or less in combination of these alkyl groups and the alicyclic hydrocarbon group.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.
m1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1'is preferably 0 or 1.

As the structural unit (a1-0), for example, a structural unit represented by any one of the formulas (a1-0-1) to (a1-0-12) and a methyl group corresponding to R ^a01 are used as hydrogen atoms. Examples thereof include the replaced structural units, and structural units represented by any of the formulas (a1-0-1) to (a1-0-10) are preferable.

Examples of the structural unit (a1-1) include structural units derived from the monomers described in JP-A-2010-204646. Above all, the structural unit represented by any of the formulas (a1-1-1) to (a1-1-4) is preferable.

The structural unit (a1-2) includes a structural unit represented by any of the formulas (a1-2-1) to (a1-2-6) and a methyl group corresponding to R ^a01 , R ^a4 and R ^a5 . The structural unit in which is replaced with a hydrogen atom is mentioned, and more preferably, the structural unit represented by the formula (a1-2-2) or the formula (a1-2-5) is preferable.

When the resin (A) contains a structural unit (a1-0) and / or a structural unit (a1-1) and / or a structural unit (a1-2), the total content of these is the total structure of the resin (A). It is usually 10 to 95 mol%, preferably 15 to 90 mol%, and more preferably 20 to 85 mol% with respect to the total of the units.

［式（ａ１－５）中、
Ｒ^a8は、ハロゲン原子を有してもよい炭素数１～６のアルキル基、水素原子又はハロゲン原子を表す。
Ｚ^a1は、単結合又は＊－（ＣＨ₂）_h3－ＣＯ－Ｌ⁵⁴－を表し、ｈ３は１～４のいずれかの整数を表し、＊は、Ｌ⁵¹との結合手を表す。
Ｌ⁵¹、Ｌ⁵²、Ｌ⁵³及びＬ⁵⁴は、それぞれ独立に、－Ｏ－又は－Ｓ－を表す。
ｓ１は、１～３のいずれかの整数を表す。
ｓ１’は、０～３のいずれかの整数を表す。 Examples of the structural unit having an acid unstable group include a structural unit represented by the formula (a1-5) (hereinafter, may be referred to as “structural unit (a1-5)”).

[In equation (a1-5),
R ^a8 represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom or a halogen atom which may have a halogen atom.
Z ^a1 represents a single bond or *-(CH ₂ ) _h3 -CO-L ^54- , h3 represents an integer of 1 to 4, and * represents a bond with L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ independently represent -O- or -S-, respectively.
s1 represents an integer of 1 to 3.
s1'represents an integer of 0 to 3.

Examples of the halogen atom include a fluorine atom and a chlorine atom, and preferably a fluorine atom. Alkyl groups having 1 to 6 carbon atoms which may have a halogen atom include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, fluoromethyl group and trifluoromethyl. Group is mentioned.
In the formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
It is preferable that one of L ⁵² and L ⁵³ is -O- and the other is -S-.
As s1, 1 is preferable.
As s1', any integer of 0 to 2 is preferable.
As Z ^a1 , a single bond or * -CH ₂ -CO-O- is preferable.

Examples of the monomer for deriving the structural unit (a1-5) include the monomers described in JP-A-2010-61117. Among them, structural units derived from the monomers represented by the formulas (a1-5-1) to (a1-5-4) are preferable, and the formula (a1-5-1) or the formula (a1-5-2) is preferable. The structural unit represented by is more preferable.

When the resin (A) has a structural unit (a1-5), the content thereof is preferably 1 to 50 mol% with respect to the total of all the structural units of the resin (A), and 3 to 45. It is more preferably mol%, and even more preferably 5-40 mol%.

Further, as the structural unit (a1), the structural unit (a1-3) shown below can also be mentioned.

［式（ａ１－４）中、
Ｒ^a32は、水素原子、ハロゲン原子、又は、ハロゲン原子を有していてもよい炭素数１～６のアルキル基を表す。
Ｒ^a33は、ハロゲン原子、ヒドロキシ基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数２～４のアルキルカルボニル基、炭素数２～４のアルキルカルボニルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
ｌａは０～４のいずれかの整数を表す。ｌａが２以上である場合、複数のＲ^a33は互いに同一であっても異なってもよい。
Ｒ^a34及びＲ^a35はそれぞれ独立に、水素原子又は炭素数１～１２の炭化水素基を表し、Ｒ^a36は、炭素数１～２０の炭化水素基を表すか、Ｒ^a35及びＲ^a36は互いに結合してそれらが結合する－Ｃ－Ｏ－とともに炭素数２～２０の２価の炭化水素基を形成し、該炭化水素基及び該２価の炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－Ｓ－で置き換わってもよい。］ The structural unit having a group represented by the formula (2) in the structural unit (a1) may be referred to as a structural unit represented by the formula (a1-4) (hereinafter, "structural unit (a1-4)". .) Can be mentioned.

[In equation (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, and acryloyl. Represents an oxy group or a methacryloyloxy group.
la represents an integer of 0 to 4. When la is 2 or more, a plurality of Ra ^33s may be the same or different from each other.
R ^a34 and R ^a35 independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^a35 and R ^a36 are bonded to each other. Then, together with -CO- to which they are bonded, a divalent hydrocarbon group having 2 to 20 carbon atoms is formed, and the hydrocarbon group and -CH _2- contained in the divalent hydrocarbon group are-. It may be replaced by O- or -S-. ]

Examples of the alkyl group in R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group and the like. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.
Examples of the halogen atom in R ^a32 and R ^a33 include a fluorine atom, a chlorine atom and a bromine atom.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group and 1,1. , 2,2-Tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-Octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, etc. Can be mentioned.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group and the like. Of these, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is even more preferable.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group and the like.
Examples of the hydrocarbon group in R ^a34 , R ^a35 and R ^a36 include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining these, and an alkyl group and an alicyclic hydrocarbon group. Examples thereof include groups similar to the alkyl groups and alicyclic hydrocarbon groups in R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 .
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group and biphenyl. Examples thereof include an aryl group such as a group, a phenanthryl group, a 2,6-diethylphenyl group and a 2-methyl-6-ethylphenyl group.
Examples of the combined group include a group combining the above-mentioned alkyl group and an alicyclic hydrocarbon group, an aralkyl group such as a benzyl group, and an aryl-cyclohexyl group such as a phenylcyclohexyl group. In particular, ^Ra36 includes an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining them. Can be mentioned.

In the formula (a1-4), a hydrogen atom is preferable as R ^a32 .
As R ^a33 , an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group and an ethoxy group are more preferable, and a methoxy group is further preferable.
As la, 0 or 1 is preferable, and 0 is more preferable.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably an alkyl group or an alicyclic hydrocarbon group having 1 to 12 carbon atoms, and more preferably a methyl group or an ethyl group.
The hydrocarbon group of R ^a36 is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. It is a group to be formed, more preferably an alkyl group having 1 to 18 carbon atoms, an aliphatic hydrocarbon group having 3 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and alicyclic hydrocarbon group in R ^a36 are preferably unsubstituted. The aromatic hydrocarbon group in R ^a36 is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

Examples of the structural unit (a1-4) include structural units derived from the monomers described in JP-A-2010-204646. Preferably, the structural unit represented by the formulas (a1-4-1) to (a1-4-8) and the structure in which the hydrogen atom corresponding to ^Ra32 in the structural unit (a1-4) is replaced with a methyl group. Units are mentioned, and more preferably, structural units represented by the formulas (a1-4-1) to (a1-4-5) are mentioned.

樹脂（Ａ）が構造単位（ａ１－３）又は構造単位（ａ１－４）を含む場合、その含有率は、樹脂（Ａ）の全構造単位に対して、１０～９５モル％が好ましく、１５～９０モル％がより好ましく、２０～８５モル％がさらに好ましい。

When the resin (A) contains a structural unit (a1-3) or a structural unit (a1-4), the content thereof is preferably 10 to 95 mol% with respect to all the structural units of the resin (A), and 15 It is more preferably from 90 mol%, still more preferably from 20 to 85 mol%.

The structural unit (a1) having an acid unstable group in the resin (A) is at least selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2). One or more are preferable, at least two or more are more preferable, a combination of structural units (a1-1) and structural units (a1-2), combinations of structural units (a1-1) and structural units (a1-0), and structures. A combination of the unit (a1-2) and the structural unit (a1-0), a combination of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2) are more preferable, and the structural unit (a1-2) is more preferable. The combination of a1-1) and the structural unit (a1-2) is particularly preferable.

<Structural unit without acid unstable group (s)>
The structural unit (s) is derived from a monomer having no acid unstable group (hereinafter, may be referred to as “monomer (s)”). As the monomer (s) for deriving the structural unit (s), a monomer having no acid unstable group known in the resist field can be used.
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid unstable group is preferable. A structure having a hydroxy group and no acid unstable group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structure having a lactone ring and no acid unstable group. If a resin having a unit (hereinafter sometimes referred to as "structural unit (a3)") is used in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group of the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When a resist pattern is produced from the resist composition of the present invention, when a high energy ray such as a KrF excimer laser (248 nm), an electron beam or EUV (ultraviolet light) is used as an exposure light source, the structural unit (a2) is used. , It is preferable to include a structural unit (a2) having a phenolic hydroxy group. When an ArF excimer laser (193 nm) or the like is used, it is preferable that the structural unit (a2) includes a structural unit (a2) having an alcoholic hydroxy group. As the structural unit (a2), one type may be contained alone, or two or more types may be contained.
When the resin (A) has a structural unit (a2-0) having a phenolic hydroxy group, the content thereof is preferably 5 to 95 mol% with respect to all the structural units of the resin (A), and 10 to 10 to 80 mol% is more preferable, and 15-80 mol% is even more preferable.

［式（ａ２－１）中、
Ｌ^a3は、－Ｏ－又は＊－Ｏ－（ＣＨ₂）_k2－ＣＯ－Ｏ－を表し、
ｋ２は、１～７のいずれかの整数を表す。＊は－ＣＯ－との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０～１０のいずれかの整数を表す。］ Examples of the structural unit (a2) having an alcoholic hydroxy group include structural units represented by the formula (a2-1) (hereinafter, may be referred to as “structural unit (a2-1)”).

[In equation (a2-1),
L ^a3 represents -O- or * -O- (CH ₂ ) _k2 -CO-O-
k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 independently represent a hydrogen atom, a methyl group or a hydroxy group, respectively.
o1 represents an integer of 0 to 10. ]

In the formula (a2-1), ^La3 is preferably -O-, -O- (CH ₂ ) _f1 -CO-O- (the f1 is an integer of 1 to 4). , More preferably -O-.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, and more preferably 0 or 1.

Examples of the monomer for inducing the structural unit (a2-1) include the monomers described in JP-A-2010-204646. The structural unit represented by any of the formulas (a2-1-1) to (a2-1-6) is preferable, and any of the formulas (a2-1-1) to (a2-1-4) is preferable. The structural unit represented is more preferable, and the structural unit represented by the formula (a2-1-1) or the formula (a2-1-3) is further preferable.

When the resin (A) contains a structural unit (a2) having an alcoholic hydroxy group, the content thereof is usually 1 to 45 mol%, preferably 1 to 1 to all the structural units of the resin (A). It is 40 mol%, more preferably 1 to 35 mol%, still more preferably 2 to 20 mol%.

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocyclic ring such as β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a fused ring of a monocyclic lactone ring and another ring. However, the lactone ring preferably includes a γ-butyrolactone ring, an adamantan lactone ring, or a crosslinked ring containing a γ-butyrolactone ring structure.

［式（ａ３－１）、式（ａ３－２）、式（ａ３－３）及び式（ａ３－４）中、
Ｌ^ａ４、Ｌ^ａ５及びＬ^ａ６は、－Ｏ－又は^＊－Ｏ－（ＣＨ_２）_ｋ３－ＣＯ－Ｏ－（ｋ３は１～７のいずれかの整数を表す。）で表される基を表す。
Ｌ^ａ７は、－Ｏ－、^＊－Ｏ－Ｌ^ａ８－Ｏ－、^＊－Ｏ－Ｌ^ａ８－ＣＯ－Ｏ－、^＊－Ｏ－Ｌ^ａ８－ＣＯ－Ｏ－Ｌ^ａ９－ＣＯ－Ｏ－又は^＊－Ｏ－Ｌ^ａ８－Ｏ－ＣＯ－Ｌ^ａ９－Ｏ－を表す。
Ｌ^ａ８及びＬ^ａ９は、それぞれ独立に、炭素数１～６のアルカンジイル基を表す。
＊はカルボニル基との結合手を表す。
Ｒ^ａ１８、Ｒ^ａ１９及びＲ^ａ２０は、水素原子又はメチル基を表す。
Ｒ^ａ２４は、ハロゲン原子を有してもよい炭素数１～６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^ａ２１は炭素数１～４の脂肪族炭化水素基を表す。
Ｒ^ａ２２、Ｒ^ａ２３及びＲ^ａ２５は、カルボキシ基、シアノ基又は炭素数１～４の脂肪族炭化水素基を表す。
ｐ１は０～５のいずれかの整数を表す。
ｑ１は、０～３のいずれかの整数を表す。
ｒ１は、０～３のいずれかの整数を表す。
ｗ１は、０～８のいずれかの整数を表す。
ｐ１、ｑ１、ｒ１及び／又はｗ１が２以上のとき、複数のＲ^ａ２１、Ｒ^ａ２２、Ｒ^ａ２３及び／又はＲ^ａ２５は互いに同一であってもよく、異なってもよい。］ The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3) or the formula (a3-4). The resin (A) may contain one of these types alone, or may contain two or more types of the resin (A).

[In the formula (a3-1), the formula (a3-2), the formula (a3-3) and the formula (a3-4),
L ^a4 , ^La 5 and ^{La 6} represent a group represented by -O- or ^* -O- (CH ₂ ) _k3 -CO-O- (k3 represents an integer of 1 to 7). ..
L ^a7 is -O-, ^* -OL ^a8 -O-, ^{* -OL a8-CO-O-, * -OL a8 -} CO-O-L ^a9 -CO-O- or ^* -O-L ^a8 -O-CO-L ^a9 -O-represented.
L ^a8 and ^{La 9} each independently represent an alkanediyl group having 1 to 6 carbon atoms.
* Represents a bond with a carbonyl group.
R ^a18 , R ^a19 and R ^a20 represent a hydrogen atom or a methyl group.
R ^a24 represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom or a halogen atom which may have a halogen atom.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
R ^a22 , R ^a23 and R ^a25 represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5.
q1 represents an integer of 0 to 3.
r1 represents any integer from 0 to 3.
w1 represents any integer from 0 to 8.
When p1, q1, r1 and / or w1 is 2 or more, the plurality of R ^a21 , R ^a22 , R ^a23 and / or R ^a25 may be the same or different from each other. ]

The aliphatic hydrocarbon groups of R ^a21 , Ra ²² and Ra ²³ include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group. Can be mentioned.
Examples of the halogen atom of ^Ra24 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkyl group of R ^a24 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group and an n-hexyl group. An alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.
Alkyl groups having a halogen atom of ^Ra24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and perfluoro. Examples thereof include a hexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.

The alkanediyl groups of ^La8 and ^La9 include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group and pentane-1,5. -Diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, Examples thereof include a 4-diyl group and a 2-methylbutane-1,4-diyl group.

（式中、Ｒ^ａ２４、Ｌ^ａ７は、上記と同じ意味を表す。） In the formulas (a3-1) to (a3-4), ^La4 to ^La6 are independently, preferably -O-, or k3 is an integer of any one of 1 to 4 * -O- ( CH ₂ ) A group represented by _k3 -CO—O—, more preferably —O— and * —O— _CH2 -CO—O—, and even more preferably an oxygen atom.
L ^a7 is preferably -O- or ^* -OL ^a8 -CO-O-, and more preferably -O-, -O-CH ₂ -CO-O- or -O-C ₂ H _4- . It is CO-O-.
R ^a18 to R ^a21 are preferably methyl groups.
^Ra24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and further preferably a hydrogen atom or a methyl group.
R ^a22 , R ^a23 and R ^a25 are each independently, preferably a carboxy group, a cyano group or a methyl group.
p1, q1, r1 and w1 are independently, preferably an integer of 0 to 2, and more preferably 0 or 1.
The formula (a3-4) is particularly preferably the formula (a3-4)'.

(In the formula, ^Ra24 and ^La7 have the same meanings as above.)

Examples of the monomer for deriving the structural unit (a3) include the monomers described in JP-A-2010-204646, the monomers described in JP-A-2000-122294, and the monomers described in JP-A-2012-41274. Can be mentioned. As the structural unit (a3), a structural unit represented by any of the following is preferable, and the formula (a3-1-1), the formula (a3-2-1), the formula (a3--2-2), and the formula (a3-2-2) are preferable. The structural unit represented by any of a3-4-1) to the formula (a3-4-6) is more preferable, and the formula (a3-1-1), the formula (a3-2-3) or the formula (a3-). The structural unit represented by 4-2) is more preferable.

上記構造単位においては、Ｒ^ａ１８、Ｒ^ａ１９、Ｒ^ａ２０及びＲ^ａ２４に相当するメチル基が水素原子に置き換わった化合物も、構造単位（ａ３）の具体例として挙げられる。

In the above structural unit, a compound in which a methyl group corresponding to ^Ra 18, ^{Ra 19} , ^Ra 20 and Ra 24 is replaced with a hydrogen atom is also mentioned as a specific example of the structural unit (a3).

When the resin (A) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A). , More preferably 10-60 mol%.
The content of each of the structural units represented by the formula (a3-1), the formula (a3-2), the formula (a3-3) and the formula (a3-4) is the total structural unit of the resin (A). , Usually 5 to 60 mol%, preferably 5 to 50 mol%, more preferably 10 to 50 mol%.

<Other structural units (t)>
The resin (A) may contain other structural units (t) as structural units other than the structural unit (a1) and the structural unit (s). As the structural unit (t), a structural unit having a halogen atom in addition to the structural unit (a2) and the structural unit (a3) (hereinafter, sometimes referred to as “structural unit (a4)”) and a non-desorbed hydrocarbon group are used. Examples thereof include structural units that may be possessed (hereinafter, may be referred to as “structural unit (a5)”).

［式（ａ４－０）中、
Ｒ^５５は、水素原子又はメチル基を表す。
Ｌ^５は、単結合又は炭素数１～４の脂肪族飽和炭化水素基を表す。
Ｌ^３は、炭素数１～８のペルフルオロアルカンジイル基又は炭素数５～１２のペルフルオロシクロアルカンジイル基を表す。
Ｒ^６は、水素原子又はフッ素原子を表す。］ <Structural unit (a4)>
As the halogen atom in the structural unit (a4), a fluorine atom is preferable. Examples of the structural unit (a4) include a structural unit represented by the formula (a4-0).

[In equation (a4-0),
R ⁵⁵ represents a hydrogen atom or a methyl group.
L ⁵ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 5 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

Examples of the aliphatic saturated hydrocarbon group of L5 include an alkanediyl group having 1 to ⁴ carbon atoms, for example, a methylene group, an ethylene group, a propane-1,3-diyl group and a butane-1,4-diyl group. Such as linear alkanediyl group, linear alkanediyl group having an alkyl group (among others, methyl group, ethyl group, etc.) side chain, ethane-1,1-diyl group, propane-1,2 Examples thereof include branched alkanediyl groups such as a diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group and a 2-methylpropane-1,2-diyl group.

The perfluoroalkanediyl group of L ³ includes a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, and a perfluoropropane. -2,2-diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane -2,2-diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane -1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane Examples thereof include -2,2-diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like.
Examples of the perfluorocycloalkanediyl group of L3 include a perfluorocyclohexanediyl group ^, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantandiyl group and the like.

^L5 is preferably a single bond, a methylene group or an ethylene group, and more preferably a single bond or a methylene group.
L ³ is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

Examples of the structural unit (a4-0) include the following.

上記の構造単位において、Ｒ⁵に相当するメチル基が水素原子に置き換わった構造単位も、構造単位（ａ４－０）の具体例として挙げることができる。

In the above structural unit, a structural unit in which a methyl group corresponding to R ⁵ is replaced with a hydrogen atom can also be mentioned as a specific example of the structural unit (a4-0).

［式（ａ４－１）中、
Ｒ^ａ４１は、水素原子又はメチル基を表す。
Ｒ^ａ４２は、置換基を有していてもよい炭素数１～２０の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
Ａ^ａ４１は、置換基を有していてもよい炭素数１～６のアルカンジイル基又は式（ａ－ｇ１）で表される基を表す。ただし、Ａ^ａ４１及びＲ^ａ４２のうち少なくとも１つは、置換基としてハロゲン原子（好ましくはフッ素原子）を有する。

〔式（ａ－ｇ１）中、
ｓは０又は１を表す。
Ａ^a42及びＡ^a44は、それぞれ独立に、置換基を有していてもよい炭素数１～５の２価の脂肪族炭化水素基を表す。
Ａ^a43は、置換基を有していてもよい炭素数１～５の２価の脂肪族炭化水素基又は単結合を表す。
Ｘ^a41及びＸ^a42は、それぞれ独立に、－Ｏ－、－ＣＯ－、－ＣＯ－Ｏ－又は－Ｏ－ＣＯ－を表す。
ただし、Ａ^a42、Ａ^a43、Ａ^a44、Ｘ^a41及びＸ^a42の炭素数の合計は６以下である。〕
Ａ^a41及びＲ^a42のうち少なくとも一方は、置換基としてハロゲン原子を有する基である。
＊、＊＊は結合手であり、＊が－Ｏ－ＣＯ－Ｒ^ａ４２との結合手である。］
ｓは０が好ましい。 Examples of the structural unit (a4) include a structural unit represented by the equation (a4-1).

[In equation (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH _2- contained in the hydrocarbon group may be replaced with -O- or -CO-. good.
^Aa41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by the formula (ag1). However, at least one of ^Aa41 and ^Ra42 has a halogen atom (preferably a fluorine atom) as a substituent.

[In the formula (ag1),
s represents 0 or 1.
A a ⁴² and A a ⁴⁴ each independently represent a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a divalent aliphatic hydrocarbon group or a single bond having 1 to 5 carbon atoms which may have a substituent.
X ^a41 and X ^a42 independently represent -O-, -CO-, -CO-O- or -O-CO-, respectively.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 6 or less. ]
At least one of A ^a41 and R ^a42 is a group having a halogen atom as a substituent.
* And ** are bonds, and * is a bond with -O-CO-R ^a42 . ]
s is preferably 0.

芳香族炭化水素基としては、例えば、フェニル基、ナフチル基、アントリル基、ビフェニリル基、フェナントリル基及びフルオレニル基等が挙げられる。 Examples of the hydrocarbon group of R ^a42 include chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these groups. Chain-type aliphatic hydrocarbon groups include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, hexadecyl group, pentadecyl group and hexyldecyl group. , Heptadecyl group, octadecyl group and other alkyl groups. Cyclic alicyclic fatty group hydrocarbon groups include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (*). Represents a bond.) Examples thereof include a polycyclic alicyclic hydrocarbon group.

Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a biphenylyl group, a phenanthryl group and a fluorenyl group.

As the hydrocarbon group of R ^a42 , a chain type or a cyclic type aliphatic hydrocarbon group and a group formed by combining these are preferable. These groups may have a carbon-carbon unsaturated bond, but chain and cyclic aliphatic saturated hydrocarbon groups and groups formed by combining them are more preferable.

［式（ａ－ｇ３）中、
Ｘ^a43は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^a45は、少なくとも１つのハロゲン原子を有する炭素数１～１７の脂肪族炭化水素基を表す。
＊はカルボニル基との結合手を表す。］ Examples of the substituent of R ^a42 include a halogen atom and a group represented by the formula (ag3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.

[In the formula (ag3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms having at least one halogen atom.
* Represents a bond with a carbonyl group. ]

Examples of the aliphatic hydrocarbon group of A ^a45 include the same groups as those exemplified in R ^a42 .
R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, and more preferably an alkyl group having a halogen atom and / or an aliphatic hydrocarbon group having a group represented by the formula (ag3). ..

When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and further preferably having a carbon number of carbons. It is a perfluoroalkyl group of 1 to 6, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group.

When R ^a42 is an aliphatic hydrocarbon group having a group represented by the formula (ag3), the aliphatic hydrocarbon includes the number of carbon atoms contained in the group represented by the formula (ag3). The total carbon number of the group is preferably 15 or less, more preferably 12 or less. When the group represented by the formula (ag3) is used as a substituent, the number thereof is preferably one.

［式（ａ－ｇ２）中、
Ａ^a46は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
Ｘ^a44は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
ただし、Ａ^a46、Ａ^a47及びＸ^a44の炭素数の合計は１８以下であり、Ａ^a46及びＡ^a47のうち、少なくとも一方は、少なくとも１つのハロゲン原子を有する。
＊はカルボニル基との結合手を表す。］ Aliphatic hydrocarbons having a group represented by the formula (ag3) are more preferably a group represented by the formula (ag2).

[In the formula (ag2),
A ^a46 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents a carbonyloxy group or an oxycarbonyl group.
A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47 and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* Represents a bond with a carbonyl group. ]

The aliphatic hydrocarbon group of A ^a46 preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.
The aliphatic hydrocarbon group of A ^a47 preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, and even more preferably a cyclohexyl group or an adamantyl group.

Examples of the group represented by the formula (ag2) include the following groups.

The alkanediyl group of A ^a41 is a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group. Linear alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, etc. Examples thereof include a branched alkanediyl group such as 2-methylbutane-1,4-diyl group.
Examples of the substituent in the alkanediyl group of A ^a41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and further preferably an ethylene group.

Examples of the aliphatic hydrocarbon groups of A ^a42 , A ^a43 and A ^a44 in the group represented by the formula (a-g1) (hereinafter, sometimes referred to as "group (a-g1)") include a methylene group and an ethylene group. , Propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group Examples include a group, a 2-methylpropane-1,2-diyl group and the like. Examples of these substituents include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.

Examples of the group (ag1) in which X ^a42 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group include the following groups. In the following examples, * and ** represent the bond, respectively, and ** is the bond with -O-CO-R ^a42 .

［式（ａ４－２）中、
Ｒ^ｆ1は、水素原子又はメチル基を表す。
Ａ^ｆ1は、炭素数１～６のアルカンジイル基を表す。
Ｒ^ｆ2は、フッ素原子を有する炭素数１～１０の炭化水素基を表す。］ As the structural unit represented by the formula (a4-1), the structural unit represented by the formula (a4-2) and the formula (a4-3) is preferable.

[In equation (a4-2),
R ^f1 represents a hydrogen atom or a methyl group.
A ^f1 represents an alkanediyl group having 1 to 6 carbon atoms.
R ^f2 represents a hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom. ]

The alkanediyl group of A ^f1 includes a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. , Hexine-1,6-diyl group and other linear alkanediyl groups; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 Examples thereof include a branched alkanediyl group such as a diyl group, a 1-methylbutane-1,4-diyl group and a 2-methylbutane-1,4-diyl group.

The hydrocarbon group of R ^f2 includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and the aliphatic hydrocarbon group includes a chain type, a cyclic type and a group formed by a combination thereof. As the aliphatic hydrocarbon group, an alkyl group and an alicyclic hydrocarbon group are preferable.
Alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group and 2 -Examples include ethylhexyl groups.
The alicyclic hydrocarbon group may be either a monocyclic group or a polycyclic group, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and a methylcyclohexyl group. , Cycloalkyl groups such as dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, and a norbornyl group. Examples thereof include a methylnorbornyl group and an isobornyl group.

Examples of the hydrocarbon group having a fluorine atom of R ^f2 include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
Specifically, examples of the alkyl group having a fluorine atom include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, and a 2,2,2-trifluoroethyl group. Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2 , 2,2-Tetrafluoroethyl group, Perfluoropropyl group, 1,1,2,2-Tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2, 2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2,2,3,3 , 4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group and perfluorohexyl Fluoroalkyl groups such as groups can be mentioned.
Examples of the alicyclic hydrocarbon group having a fluorine atom include a fluorocycloalkyl group such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

In the formula (a4-2), A ^f1 is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.
As R ^f2 , an alkyl fluoride group having 1 to 6 carbon atoms is preferable.

［式（ａ４－３）中、
Ｒ^ｆ11は、水素原子又はメチル基を表す。
Ａ^ｆ11は、炭素数１～６のアルカンジイル基を表す。
Ａ^ｆ13は、フッ素原子を有していてもよい炭素数１～１８の脂肪族炭化水素基を表す。
Ｘ^ｆ12は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^ｆ14は、フッ素原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。 ただし、Ａ^ｆ13及びＡ^ｆ14の少なくとも１つは、フッ素原子を有する脂肪族炭化水素基を表す。］

[In equation (a4-3),
R ^f11 represents a hydrogen atom or a methyl group.
A ^f11 represents an alkanediyl group having 1 to 6 carbon atoms.
A ^f13 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a fluorine atom.
X ^f12 represents a carbonyloxy group or an oxycarbonyl group.
A ^f14 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom. However, at least one of A ^f13 and A ^f14 represents an aliphatic hydrocarbon group having a fluorine atom. ]

Examples of the alkanediyl group of A ^f11 include the same groups as the alkanediyl group of A ^f1 .

The aliphatic hydrocarbon group of A ^f13 includes either a chain type or a cyclic type, and a divalent aliphatic hydrocarbon group formed by combining them. This aliphatic hydrocarbon may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f13 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group.
Examples of the divalent chain aliphatic hydrocarbon group which may have a fluorine atom include an alkanediyl group such as a methylene group, an ethylene group, a propanediyl group, a butanjiyl group and a pentandiyl group; a difluoromethylene group and a perfluoroethylene group. Examples thereof include a perfluoroalkandyl group such as a group, a perfluoropropanediyl group, a perfluorobutandyl group and a perfluoropentanediyl group.
The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic aliphatic hydrocarbon group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic divalent aliphatic hydrocarbon group include an adamantandiyl group, a norbornanediyl group, and a perfluoroadamantandiyl group.

The aliphatic hydrocarbon group of A ^f14 includes either a chain type or a cyclic type, and an aliphatic hydrocarbon group formed by combining them. This aliphatic hydrocarbon may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f14 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom.
Chain-type aliphatic hydrocarbon groups that may have a fluorine atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, and 1,1. , 2,2-Tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-Octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, Examples thereof include a heptyl group, a perfluoroheptyl group, an octyl group and a perfluorooctyl group.
The cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the group containing a monocyclic aliphatic hydrocarbon group include a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group and a perfluorocyclohexyl group. Examples of the group containing a polycyclic aliphatic hydrocarbon group include an adamantyl group, an adamantylmethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, a perfluoroadamantylmethyl group and the like.

In the formula ( ^a4-3 ), an ethylene group is preferable as A f11.
The aliphatic hydrocarbon group of A ^f13 preferably has 1 to 6 carbon atoms, and more preferably 2 to 3 carbon atoms.
The aliphatic hydrocarbon group of A ^f14 preferably has 3 to 12 carbon atoms, and more preferably 3 to 10 carbon atoms. Among them, A ^f14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group.

As the structural unit represented by the formula (a4-2), the structural unit represented by the formulas (a4-1-1) to (a4-1-11) and the methyl group corresponding to R ^f1 are used as hydrogen atoms. Examples include the replaced structural units.

Examples of the structural unit represented by the formula (a4-3) include the following structural units and structural units in which a methyl group corresponding to R ^f11 is replaced with a hydrogen atom.

Examples of the structural unit (a4) include the structural units described below.

When the resin (A) has a structural unit (a4), the content thereof is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and 3) with respect to all the structural units of the resin (A). -10 mol% is more preferred.

［式（ａ５－１）中、
Ｒ⁵¹は、水素原子又はメチル基を表す。
Ｒ⁵²は、炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる水素原子は炭素数１～８の脂肪族炭化水素基で置換されていてもよい。但し、Ｌ⁵⁵との結合位置にある炭素原子に結合する水素原子は、炭素数１～８の脂肪族炭化水素基で置換されない。
Ｌ⁵⁵は、単結合又は炭素数１～１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］ <Structural unit (a5)>
Examples of the non-desorbing hydrocarbon group contained in the structural unit (a5) include a linear, branched or cyclic hydrocarbon group, and preferably a group having an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1).

[In equation (a5-1),
R ⁵¹ represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. .. However, the hydrogen atom bonded to the carbon atom at the bond position with L ⁵⁵ is not substituted with the aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

The alicyclic hydrocarbon group of R ⁵² may be either a monocyclic or polycyclic group. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group.
Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group and a hexyl group. , Octyl groups and alkyl groups such as 2-ethylhexyl groups.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group.
R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

Examples of the divalent saturated hydrocarbon group of L ⁵⁵ include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and a divalent aliphatic saturated hydrocarbon group is preferable. ..
Examples of the divalent aliphatic saturated hydrocarbon group include an alkanediyl group such as a methylene group, an ethylene group, a propanediyl group, a butanjiyl group and a pentandiyl group.
The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include a cycloalkanediyl group such as a cyclopentanediyl group and a cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantandiyl group and a norbornanediyl group.

式（Ｌ１－１）中、
Ｘ^x1は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ｌ^x1は、炭素数１～１６の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x2は、単結合又は炭素数１～１５の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x1及びＬ^x2の合計炭素数は、１６以下である。
式（Ｌ１－２）中、
Ｌ^x3は、炭素数１～１７の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x4は、単結合又は炭素数１～１６の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x1及びＬ^x2の合計炭素数は、１７以下である。
式（Ｌ１－３）中、
Ｌ^x5は、炭素数１～１５の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x6及びＬ^x７は、それぞれ独立に、単結合又は炭素数１～１４の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x5、Ｌ^x6及びＬ^x7の合計炭素数は、１５以下である。
式（Ｌ１－４）中、
Ｌ^x8及びＬ^x9は、それぞれ独立に、単結合又は炭素数１～１２の２価の脂肪族飽和炭化水素基を表す。
Ｗ^x1は、炭素数３～１５の２価の脂環式飽和炭化水素基を表す。
ただし、Ｌ^x8、Ｌ^x9及びＷ^x1の合計炭素数は、１５以下である。 Examples of the group in which the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group include groups represented by the formulas (L1-1) to (L1-4). In the following formula, * represents a bond with an oxygen atom.

In equation (L1-1),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total number of carbon atoms of L ^x 1 and L ^{x 2} is 16 or less.
In equation (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total number of carbon atoms of L ^x 1 and L ^{x 2} is 17 or less.
In formula (L1-3),
L ^{x 5} represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of L ^x5 , L ^x6 and L ^x7 is 15 or less.
In formula (L1-4),
L ^x8 and L ^x9 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x 1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total carbon number of L ^x8 , L ^x9 and W ^x1 is 15 or less.

L ^x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond.
L ^x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^{x 5} is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group.
L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.
L ^x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.
W ^x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, and more preferably a cyclohexanediyl group or an adamantanediyl group.

Examples of the group represented by the formula (L1-1) include the divalent group shown below.

Examples of the group represented by the formula (L1-2) include the divalent group shown below.

Examples of the group represented by the formula (L1-3) include the divalent group shown below.

Examples of the group represented by the formula (L1-4) include the divalent group shown below.

L ⁵⁵ is preferably a single bond, a methylene group, an ethylene group or a group represented by the formula (L1-1), and more preferably a single bond or a group represented by the formula (L1-1). ..

Examples of the structural unit (a5-1) include the following structural units and structural units in which a methyl group corresponding to R ⁵¹ is replaced with a hydrogen atom.

When the resin (A) has a structural unit (a5), the content thereof is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and 3) with respect to all the structural units of the resin (A). It is more preferably ~ 15 mol%.

The resin (A) is preferably a resin composed of a structural unit (a1) and a structural unit (s), that is, a copolymer of a monomer (a1) and a monomer (s).
The structural unit (s) is preferably at least one of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably a structural unit represented by the formula (a2-1). The structural unit (a3) is preferably a structural unit represented by the formulas (a3-1-1) to (a3-1-4), and the formulas (a3-2-1) to the formula (a3-2-4). And at least one selected from the structural units represented by the formulas (a3-4-1) to the formula (a3-4-2).

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer for inducing these structural units. can do. The content of each structural unit of the resin (A) can be adjusted by adjusting the amount of the monomer used for the polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, still more preferable). Is 15,000 or less). In the present specification, the weight average molecular weight is a value obtained by gel permeation chromatography under the conditions described in Examples.

<Resin other than resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A). Examples of such a resin include a resin containing a structural unit (t), and a resin containing the structural unit (a4) (however, the structural unit (a1) is not included. Hereinafter referred to as “resin (X)”. There is.) Is preferable.
In the resin (X), the content of the structural unit (a4) is preferably 40 mol% or more, more preferably 45 mol% or more, still more preferably 50 mol% or more, based on all the structural units of the resin (X). ..
Examples of the structural unit that the resin (X) may further include include a structural unit (a2), a structural unit (a3), and a structural unit derived from other known monomers.
The weight average molecular weight of the resin (X) is preferably 8,000 or more (more preferably 10,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weight of the resin (X) is the same as that of the resin (A).
When the resist composition contains the resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, and further, with respect to 100 parts by mass of the resin (A). It is preferably 1 to 40 parts by mass, and particularly preferably 2 to 30 parts by mass.

The total content of the resin (A) and the resin other than the resin (A) is preferably 80% by mass or more and 99% by mass or less with respect to the solid content of the resist composition. The solid content of the resist composition and the content of the resin relative to the solid content can be measured by a known analytical means such as liquid chromatography or gas chromatography.

<Acid generator (B)>
As the acid generator (B), a known acid generator can be used, and either an ionic acid generator or a nonionic acid generator may be used. An ionic acid generator is preferred. Examples of the ionic acid generator include an ionic acid generator composed of a combination of a known cation and a known anion.

Examples of the acid generator (B) include organic sulfonic acids and organic sulfonium salts. For example, the acid generation described in JP2013-68914A, JP2013-3155, and JP2013-11905. Agents and the like can be mentioned. Specific examples thereof include those represented by the formulas (B1-1) to (B1-48), among which the formulas (B1-1) to the formulas (B1-3) containing an arylsulfonium cation and the formulas (B1-3). B1-5) to formula (B1-7), formula (B1-11) to formula (B1-14), formula (B1-17), formula (B1-20) to formula (B1-26), formula (B1) -29), those represented by the formulas (B1-31) to (B1-48), respectively, are particularly preferable.

The acid generator (B) may contain two or more kinds.
The resist composition may contain only the salt (I), or may contain the salt (I) and the acid generator (B) in combination.
When the salt (I) and the acid generator (B) are contained as the acid generator, the ratio of the contents of the salt (I) and the acid generator (B) (mass ratio, salt (I0): acid generator (B)) is usually 1:99 to 99: 1, preferably 2:98 to 98: 2, and more preferably 5:95 to 95: 5.
In the resist composition, when the salt (I) and the acid generator (B) are used as the acid generator, the contents of the salt (I) and the acid generator (B) are preferable with respect to the resin (A). Is 1% by mass or more (more preferably 3% by mass or more), preferably 40% by mass or less (more preferably 35% by mass or less).

<Solvent (E)>
The content of the solvent (E) in the resist composition is usually 90% by mass or more, preferably 92% by mass or more, more preferably 94% by mass or more, and 99.9% by mass or less. It is preferably 99% by mass or less. The content of the solvent (E) can be measured by a known analytical means such as liquid chromatography or gas chromatography.

Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate. Esters; ketones such as acetone, methylisobutylketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. One type of solvent (E) may be contained alone, or two or more types may be contained.

<Quencher (C)>
Examples of the quencher (C) include a basic nitrogen-containing organic compound or a salt that generates an acid having a weaker acidity than the acid generated from an acid generator.
Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.

Examples of amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-,3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine, hexylamine, Heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, trypentylamine, trihexylamine, tri Heptylamine, Trioctylamine, Trinonylamine, Tridecylamine, Methyldibutylamine, Methyldipentylamine, Methyldihexylamine, Methyldicyclohexylamine, Methyldiheptylamine, Methyldioctylamine, Methyldinonylamine, Methyldidecylamine, Ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, tri Isopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3 , 3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di (2-pyridyl) ethane, 1,2-di (4-di) Pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethen, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ) Etan, di (2-pyridyl) ketone, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicorylamine, bipyridine and the like. Diisopropylaniline is preferable, and 2,6-diisopropylaniline is more preferable.

Examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, and 3- (trifluoromethyl) phenyltrimethyl. Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like can be mentioned.

The acidity of a salt that produces an acid that is weaker than the acid generated by the salt (aa) and the acid generator (B) is indicated by the acid dissociation constant (pKa). A salt that generates an acid having a weaker acidity than the acid generated from the salt (aa) and the acid generator (B) usually has an acid dissociation constant of -3 <pKa. A salt of -1 <pKa <7 is preferable, and a salt of 0 <pKa <5 is more preferable.
Examples of the salt that generates an acid having a weaker acidity than the acid generated from the salt (aa) and the acid generator (B) include a salt represented by the following formula and a salt represented by the formula (D) (hereinafter, weak acid). (Sometimes referred to as an intramolecular salt (D)), JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-390502 and JP-A-2011-191745. Examples thereof include the salts described in the publication. It is preferably a salt having a weak acid content represented by the formula (D).

The content of the quencher (C) is preferably about 0.01 to 5% by mass based on the solid content of the resist composition.

<Other ingredients>
If necessary, the resist composition of the present invention may contain a component other than the above-mentioned components (hereinafter, may be referred to as "other component (F)"). The other component (F) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes and the like, can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A), a salt (I) of the present invention, a resin other than the resin (A) used as necessary, an acid generator (B), a solvent (E), and a citric acid. It can be prepared by mixing a salt that generates a weakly acidic acid such as char (C) and a weak acid intramolecular salt (D) and another component (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can be selected from 10 to 40 ° C., depending on the type of the resin or the like and the solubility of the resin or the like in the solvent (E). As the mixing time, an appropriate time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing or the like can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Manufacturing method of resist pattern>
The method for producing a resist pattern of the present invention is
(1) A step of applying the resist composition of the present invention onto a substrate,
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
It includes (4) a step of heating the composition layer after exposure and (5) a step of developing the composition layer after heating.

The resist composition can be applied onto the substrate by a commonly used device such as a spin coater. Examples of the substrate include an inorganic substrate such as a silicon wafer. The substrate may be washed before the resist composition is applied, or an antireflection film or the like may be formed on the substrate.

By drying the composition after coating, the solvent is removed and a composition layer is formed. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called prebaking), or by using a depressurizing device. The heating temperature is preferably 50 to 200 ° C., and the heating time is preferably 10 to 180 seconds. The pressure for drying under reduced pressure is preferably about ¹ to 1.0 × 105 Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. The exposure light source includes a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ excima laser (wavelength 157 nm) that emits laser light in the ultraviolet region, and a solid-state laser light source (YAG or semiconductor laser). Etc.), and various ones such as those that radiate harmonic laser light in the far ultraviolet region or vacuum ultraviolet region by radiating the laser light from, electron beam, and those that irradiate super-ultraviolet light (EUV) are used. Can be done. In addition, in this specification, irradiation of these radiations may be generically referred to as "exposure". At the time of exposure, the exposure is usually performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, it may be exposed by direct drawing without using a mask.

The composition layer after exposure is heat-treated (so-called post-exposure bake) in order to promote the deprotection reaction at the acid unstable group. The heating temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.

The heated composition layer is usually developed using a developer and a developer. Examples of the developing method include a dip method, a paddle method, a spray method, and a dynamic dispense method. The development temperature is preferably, for example, 5 to 60 ° C., and the development time is preferably, for example, 5 to 300 seconds. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any alkaline aqueous solution used in this field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly known as choline) can be mentioned. The alkaline developer may contain a surfactant.
After development, it is preferable to wash the resist pattern with ultrapure water and then remove the substrate and the water remaining on the pattern.

When a negative resist pattern is produced from the resist composition of the present invention, a developer containing an organic solvent (hereinafter, may be referred to as "organic developer") is used as the developer.
Examples of the organic solvent contained in the organic developer include a ketone solvent such as 2-hexanone and 2-heptanone; a glycol ether ester solvent such as propylene glycol monomethyl ether acetate; an ester solvent such as butyl acetate; and a glycol such as propylene glycol monomethyl ether. Examples include an ether solvent; an amide solvent such as N, N-dimethylacetamide; an aromatic hydrocarbon solvent such as anisole, and the like.
The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and further preferably substantially only the organic solvent.
Among them, as the organic developer, a developer containing butyl acetate and / or 2-heptanone is preferable. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially butyl acetate and / or 2 -It is more preferable that it is only heptanone.
The organic developer may contain a surfactant. Further, the organic developer may contain a small amount of water.
At the time of development, the development may be stopped by substituting with a solvent of a type different from that of the organic developer.

It is preferable to wash the resist pattern after development with a rinsing solution. The rinsing solution is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, and an alcohol solvent or an ester solvent is preferable.
After cleaning, it is preferable to remove the rinse liquid remaining on the substrate and the pattern.

<Use>
The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure. Yes, it is more suitable as a resist composition for ArF excimer laser exposure, and is useful for fine processing of semiconductors.

The present invention will be described in more detail with reference to examples. In the examples, "%" and "part" indicating the content or the amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value obtained by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
Column: TSKgel Multipore HXL-M x 3 + guardcolumn (manufactured by Tosoh)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ℃
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh)
The structure of the compound was confirmed by measuring the molecular peak using mass spectrometry (LC: Agilent 1100 type, MASS: Agilent LC / MSD type). In the following examples, the value of this molecular ion peak is indicated by "MASS".

式（Ｉ－３－ａ）で表される化合物１０．６部、式（Ｉ－３－ｂ）で表される塩９．６部及びアセトニトリル５０部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、Ｎ－メチルピロリジン５部を５分かけて滴下し、２３℃で１８時間攪拌した。得られた反応溶液にイオン交換水３５部を添加し、２３℃で３０分間攪拌した。その後、クロロホルム７５部を添加撹拌し、分液により有機層を回収した。回収された有機層に、５％炭酸水素ナトリウム水溶液７０部部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層に、イオン交換水７０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この操作を３回繰り返した。回収された有機層を濃縮することにより、式（Ｉ－３－ｃ）で表される塩１２．４７部を得た。 Example 1: Synthesis of salt represented by formula (I-3)

10.6 parts of the compound represented by the formula (I-3-a), 9.6 parts of the salt represented by the formula (I-3-b) and 50 parts of acetonitrile were mixed and stirred at 23 ° C. for 30 minutes. .. To the obtained mixed solution, 5 parts of N-methylpyrrolidin was added dropwise over 5 minutes, and the mixture was stirred at 23 ° C. for 18 hours. 35 parts of ion-exchanged water was added to the obtained reaction solution, and the mixture was stirred at 23 ° C. for 30 minutes. Then, 75 parts of chloroform was added and stirred, and the organic layer was recovered by liquid separation. 70 parts of a 5% aqueous sodium hydrogen carbonate solution was added to the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, separated, and the organic layer was taken out. 70 parts of ion-exchanged water was added to the recovered organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and the liquid was separated to remove the organic layer. This operation was repeated 3 times. By concentrating the recovered organic layer, 12.47 parts of a salt represented by the formula (I-3-c) was obtained.

式（Ｉ－３－ｄ）で表される塩２．７部、イオン交換水１６部及びアセトニトリル２４部を混合し、２３℃で１時間攪拌した。得られた混合溶液に式（Ｉ－３－ｃ）で表される塩６．２部、イオン交換水６．２部及びアセトニトリル１２．４部を混合し、２３℃で３６時間攪拌した。得られた反応物を濃縮し、濃縮残に、クロロホルム８０部及びイオン交換水３０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層に、イオン交換水３０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この操作を３回繰り返した。回収された有機層を濃縮することにより、式（Ｉ－３－ｅ）で表される塩６．５８部を得た。

2.7 parts of the salt represented by the formula (I-3-d), 16 parts of ion-exchanged water and 24 parts of acetonitrile were mixed and stirred at 23 ° C. for 1 hour. 6.2 parts of the salt represented by the formula (I-3-c), 6.2 parts of ion-exchanged water and 12.4 parts of acetonitrile were mixed with the obtained mixed solution, and the mixture was stirred at 23 ° C. for 36 hours. The obtained reaction product was concentrated, 80 parts of chloroform and 30 parts of ion-exchanged water were added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes and separated to remove the organic layer. To the recovered organic layer, 30 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, and the liquid was separated to take out the organic layer. This operation was repeated 3 times. By concentrating the recovered organic layer, 6.58 parts of a salt represented by the formula (I-3-e) was obtained.

式（Ｉ－３－ｅ）で表される塩２．８５部、式（Ｉ－３－ｆ）で表される化合物０．４６部及びモノクロロベンゼン２０部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．０２部を添加し、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮した。得られた残渣に、クロロホルム３５部、イオン交換水１２部及び２８％アンモニア水０．１５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１２部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮した後、得られた残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて攪拌した後、ろ過することにより、式（Ｉ－３）で表される塩１．３８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３５９．２
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３２３．０

2.85 parts of the salt represented by the formula (I-3-e), 0.46 parts of the compound represented by the formula (I-3-f) and 20 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. .. To the obtained mixed solution, 0.02 part of copper (II) dibenzoate was added, and the mixture was further stirred at 100 ° C. for 30 minutes. The obtained reaction solution was concentrated. To the obtained residue, 35 parts of chloroform, 12 parts of ion-exchanged water and 0.15 parts of 28% ammonia water were added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. Twelve parts of ion-exchanged water was added to the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 3 times. After concentrating the obtained organic layer, 30 parts of tert-butylmethyl ether was added to the obtained residue, and the mixture was stirred and then filtered to obtain 1.38 parts of a salt represented by the formula (I-3). Got
MASS (ESI (+) Spectrum): M ⁺ 359.2
MASS (ESI (-) Spectrum): M ^- 323.0

式（Ｉ－２－ｄ）で表される塩２．９部、イオン交換水１６部及びアセトニトリル２４部を混合し、２３℃で１時間攪拌した。得られた混合溶液に式（Ｉ－３－ｃ）で表される塩６．２部、イオン交換水６．２部及びアセトニトリル１２．４部を混合し、２３℃で３６時間攪拌した。得られた反応物を濃縮し、濃縮残渣に、クロロホルム８０部及びイオン交換水３０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層に、イオン交換水３０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この操作を３回繰り返した。回収された有機層を濃縮することにより、式（Ｉ－２－ｅ）で表される塩６．４４部を得た。 Example 2: Synthesis of salt represented by formula (I-2)

2.9 parts of the salt represented by the formula (I-2-d), 16 parts of ion-exchanged water and 24 parts of acetonitrile were mixed and stirred at 23 ° C. for 1 hour. 6.2 parts of the salt represented by the formula (I-3-c), 6.2 parts of ion-exchanged water and 12.4 parts of acetonitrile were mixed with the obtained mixed solution, and the mixture was stirred at 23 ° C. for 36 hours. The obtained reaction product was concentrated, 80 parts of chloroform and 30 parts of ion-exchanged water were added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes and separated to remove the organic layer. To the recovered organic layer, 30 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, and the liquid was separated to take out the organic layer. This operation was repeated 3 times. By concentrating the recovered organic layer, 6.44 parts of a salt represented by the formula (I-2-e) was obtained.

式（Ｉ－２－ｅ）で表される塩２．９部、式（Ｉ－３－ｆ）で表される化合物０．５部及びモノクロロベンゼン２０部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．０２部を添加し、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮した。得られた残渣に、クロロホルム３５部、イオン交換水１２部及び２８％アンモニア水０．１５部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層にイオン交換水１２部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮した。得られた残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて攪拌した後、ろ過することにより、式（Ｉ－２）で表される塩１．１２部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３５９．２
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３３９．１

2.9 parts of the salt represented by the formula (I-2-e), 0.5 part of the compound represented by the formula (I-3-f) and 20 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. .. To the obtained mixed solution, 0.02 part of copper (II) dibenzoate was added, and the mixture was further stirred at 100 ° C. for 30 minutes. The obtained reaction solution was concentrated. To the obtained residue, 35 parts of chloroform, 12 parts of ion-exchanged water and 0.15 parts of 28% ammonia water were added, and the mixture was stirred at 23 ° C. for 30 minutes, separated and the organic layer was taken out. Twelve parts of ion-exchanged water was added to the recovered organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and the liquid was separated to remove the organic layer. This washing operation was repeated 3 times. The obtained organic layer was concentrated. 30 parts of tert-butylmethyl ether was added to the obtained residue, and the mixture was stirred and then filtered to obtain 1.12 parts of a salt represented by the formula (I-2).
MASS (ESI (+) Spectrum): M ⁺ 359.2
MASS (ESI (-) Spectrum): M ^- 339.1

式（Ｉ－１３－ｄ）で表される塩２．７部、イオン交換水１６部及びアセトニトリル２４部を仕込み、２３℃で１時間攪拌した。得られた混合溶液に式（Ｉ－３－ｃ）で表される塩６．２部、イオン交換水６．２部及びアセトニトリル１２．４部を混合し、２３℃で３６時間攪拌した。得られた反応物を濃縮し、濃縮残渣に、クロロホルム８０部及びイオン交換水３０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層に、イオン交換水３０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この操作を３回繰り返した。回収された有機層を濃縮することにより、式（Ｉ－１３－ｅ）で表される塩６．４４部を得た。 Example 3: Synthesis of salt represented by the formula (I-13)

2.7 parts of the salt represented by the formula (I-13-d), 16 parts of ion-exchanged water and 24 parts of acetonitrile were charged and stirred at 23 ° C. for 1 hour. 6.2 parts of the salt represented by the formula (I-3-c), 6.2 parts of ion-exchanged water and 12.4 parts of acetonitrile were mixed with the obtained mixed solution, and the mixture was stirred at 23 ° C. for 36 hours. The obtained reaction product was concentrated, 80 parts of chloroform and 30 parts of ion-exchanged water were added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes and separated to remove the organic layer. To the recovered organic layer, 30 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, and the liquid was separated to take out the organic layer. This operation was repeated 3 times. By concentrating the recovered organic layer, 6.44 parts of a salt represented by the formula (I-13-e) was obtained.

式（Ｉ－１３－ｅ）で表される塩２．９部、式（Ｉ－３－ｆ）で表される化合物０．５部及びモノクロロベンゼン２０部を混合し、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．０２部を添加し、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮し、得られた残渣に、クロロホルム３５部、イオン交換水１２部及び２８％アンモニア水０．１５部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層にイオン交換水１２部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮した。得られた残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて攪拌し、ろ過することにより、式（Ｉ－１３）で表される塩１．８８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３５９．２
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３２３．１

2.9 parts of the salt represented by the formula (I-13-e), 0.5 part of the compound represented by the formula (I-3-f) and 20 parts of monochlorobenzene are mixed and stirred at 23 ° C. for 30 minutes. did. To the obtained mixed solution, 0.02 part of copper (II) dibenzoate was added, and the mixture was further stirred at 100 ° C. for 30 minutes. The obtained reaction solution is concentrated, 35 parts of chloroform, 12 parts of ion-exchanged water and 0.15 parts of 28% ammonia water are added to the obtained residue, and the mixture is stirred at 23 ° C. for 30 minutes, separated to form an organic layer. Was taken out. Twelve parts of ion-exchanged water was added to the recovered organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and the liquid was separated to remove the organic layer. This washing operation was repeated 3 times. The obtained organic layer was concentrated. To the obtained residue, 30 parts of tert-butylmethyl ether was added, stirred, and filtered to obtain 1.88 parts of a salt represented by the formula (I-13).
MASS (ESI (+) Spectrum): M ⁺ 359.2
MASS (ESI (-) Spectrum): M ^- 323.1

式（Ｉ－１３１－ａ）で表される化合物１１．５部、式（Ｉ－３－ｂ）で表される塩９．６部及びアセトニトリル５０部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、Ｎ－メチルピロリジン５部を５分かけて滴下し、２３℃で１８時間攪拌した。得られた反応溶液にイオン交換水３５部を添加し、２３℃で３０分間攪拌した。その後、クロロホルム７５部を添加撹拌し、分液により有機層を回収した。回収された有機層に、５％炭酸水素ナトリウム水溶液７０部部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層に、イオン交換水７０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この操作を３回繰り返した。回収された有機層を濃縮することにより、式（Ｉ－１３１－ｃ）で表される塩１１．２２部を得た。 Example 4: Synthesis of salt represented by formula (I-131)

11.5 parts of the compound represented by the formula (I-131-a), 9.6 parts of the salt represented by the formula (I-3-b) and 50 parts of acetonitrile were mixed and stirred at 23 ° C. for 30 minutes. .. To the obtained mixed solution, 5 parts of N-methylpyrrolidin was added dropwise over 5 minutes, and the mixture was stirred at 23 ° C. for 18 hours. 35 parts of ion-exchanged water was added to the obtained reaction solution, and the mixture was stirred at 23 ° C. for 30 minutes. Then, 75 parts of chloroform was added and stirred, and the organic layer was recovered by liquid separation. 70 parts of a 5% aqueous sodium hydrogen carbonate solution was added to the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, separated, and the organic layer was taken out. 70 parts of ion-exchanged water was added to the recovered organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and the liquid was separated to remove the organic layer. This operation was repeated 3 times. By concentrating the recovered organic layer, 11.22 parts of a salt represented by the formula (I-131-c) was obtained.

式（Ｉ－３－ｄ）で表される塩２．７部、イオン交換水１６部及びアセトニトリル２４部を混合し、２３℃で１時間攪拌した。得られた混合溶液に式（Ｉ－１３１－ｃ）で表される塩６．５部、イオン交換水６．５部及びアセトニトリル１３部を混合し、２３℃で３６時間攪拌した。得られた反応物を濃縮し、濃縮残に、クロロホルム８０部及びイオン交換水３０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層に、イオン交換水３０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この操作を３回繰り返した。回収された有機層を濃縮することにより、式（Ｉ－１３１－ｅ）で表される塩６．２８部を得た。

2.7 parts of the salt represented by the formula (I-3-d), 16 parts of ion-exchanged water and 24 parts of acetonitrile were mixed and stirred at 23 ° C. for 1 hour. 6.5 parts of the salt represented by the formula (I-131-c), 6.5 parts of ion-exchanged water and 13 parts of acetonitrile were mixed with the obtained mixed solution, and the mixture was stirred at 23 ° C. for 36 hours. The obtained reaction product was concentrated, 80 parts of chloroform and 30 parts of ion-exchanged water were added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes and separated to remove the organic layer. To the recovered organic layer, 30 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, and the liquid was separated to take out the organic layer. This operation was repeated 3 times. By concentrating the recovered organic layer, 6.28 parts of a salt represented by the formula (I-131-e) was obtained.

式（Ｉ－１３１－ｅ）で表される塩２．９４部、式（Ｉ－３－ｆ）で表される化合物０．４６部及びモノクロロベンゼン２０部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．０２部を添加し、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮した。得られた残渣に、クロロホルム３５部、イオン交換水１２部及び２８％アンモニア水０．１５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１２部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮した後、得られた残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて攪拌した後、ろ過することにより、式（Ｉ－１３１）で表される塩１．２９部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３７５．２
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３２３．０

2.94 parts of the salt represented by the formula (I-131-e), 0.46 parts of the compound represented by the formula (I-3-f) and 20 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. .. To the obtained mixed solution, 0.02 part of copper (II) dibenzoate was added, and the mixture was further stirred at 100 ° C. for 30 minutes. The obtained reaction solution was concentrated. To the obtained residue, 35 parts of chloroform, 12 parts of ion-exchanged water and 0.15 parts of 28% ammonia water were added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. Twelve parts of ion-exchanged water was added to the recovered organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 3 times. After concentrating the obtained organic layer, 30 parts of tert-butylmethyl ether was added to the obtained residue, and the mixture was stirred and then filtered to obtain 1.29 parts of a salt represented by the formula (I-131). Got
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (-) Spectrum): M ^- 323.0

式（Ｉ－２－ｄ）で表される塩２．９部、イオン交換水１６部及びアセトニトリル２４部を混合し、２３℃で１時間攪拌した。得られた混合溶液に式（Ｉ－１３１－ｃ）で表される塩６．５部、イオン交換水６．５部及びアセトニトリル１３部を混合し、２３℃で３６時間攪拌した。得られた反応物を濃縮し、濃縮残渣に、クロロホルム８０部及びイオン交換水３０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層に、イオン交換水３０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この操作を３回繰り返した。回収された有機層を濃縮することにより、式（Ｉ－１３０－ｅ）で表される塩６．２３部を得た。 Example 5: Synthesis of salt represented by formula (I-130)

2.9 parts of the salt represented by the formula (I-2-d), 16 parts of ion-exchanged water and 24 parts of acetonitrile were mixed and stirred at 23 ° C. for 1 hour. 6.5 parts of the salt represented by the formula (I-131-c), 6.5 parts of ion-exchanged water and 13 parts of acetonitrile were mixed with the obtained mixed solution, and the mixture was stirred at 23 ° C. for 36 hours. The obtained reaction product was concentrated, 80 parts of chloroform and 30 parts of ion-exchanged water were added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes and separated to remove the organic layer. To the recovered organic layer, 30 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, and the liquid was separated to take out the organic layer. This operation was repeated 3 times. By concentrating the recovered organic layer, 6.23 parts of a salt represented by the formula (I-130-e) was obtained.

式（Ｉ－１３０－ｅ）で表される塩３．０部、式（Ｉ－３－ｆ）で表される化合物０．５部及びモノクロロベンゼン２０部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．０２部を添加し、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮した。得られた残渣に、クロロホルム３５部、イオン交換水１２部及び２８％アンモニア水０．１５部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層にイオン交換水１２部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮した。得られた残渣に、ｔｅｒｔ－ブチルメチルエーテル３０部を加えて攪拌した後、ろ過することにより、式（Ｉ－１３０）で表される塩１．０１部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３７５．２
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３３９．１

3.0 parts of the salt represented by the formula (I-130-e), 0.5 part of the compound represented by the formula (I-3-f) and 20 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. .. To the obtained mixed solution, 0.02 part of copper (II) dibenzoate was added, and the mixture was further stirred at 100 ° C. for 30 minutes. The obtained reaction solution was concentrated. To the obtained residue, 35 parts of chloroform, 12 parts of ion-exchanged water and 0.15 parts of 28% ammonia water were added, and the mixture was stirred at 23 ° C. for 30 minutes, separated and the organic layer was taken out. Twelve parts of ion-exchanged water was added to the recovered organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and the liquid was separated to remove the organic layer. This washing operation was repeated 3 times. The obtained organic layer was concentrated. 30 parts of tert-butylmethyl ether was added to the obtained residue, and the mixture was stirred and then filtered to obtain 1.01 part of a salt represented by the formula (I-130).
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (-) Spectrum): M ^- 339.1

Synthesis of Resin (A) The compounds (monomers) used for the synthesis of resin (A) are shown below. Hereinafter, these compounds are referred to as "monomers (a1-1-3)" and the like according to their formula numbers.

Synthesis Example 1 [Synthesis of resin A1]
The molar ratio of the monomer (a1-1-3), the monomer (a1-2-9), the monomer (a2-1-1) and the monomer (a3-4-2) [monomer (a1-1-3): Monomer (a1-2-9): Monomer (a2-1-1): Monomer (a3-4-2)] is mixed so as to be 35: 15: 2.5: 47.5, and the total amount of the monomer is adjusted. 1.5 times by mass of propylene glycol monomethyl ether acetate was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1 mol% and 3 mol%, respectively, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was added to a mixed solvent of methanol / water, repulped, and then filtered twice to obtain a resin A1 having a weight ^average molecular weight of 8.0 × 103 in a yield of 69%. This resin A1 has the following structural units.

Synthesis Example 2 [Synthesis of resin A2]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-11), a monomer (a2-1-1) and a monomer (a3-4-2) are used, and the molar ratio [monomer (a1-1-1)] is used. -3): Monomer (a1-2-11): Monomer (a2-1-1): Monomer (a3-4-2)] was mixed so as to be 35: 15: 2.5: 47.5. Obtained a resin A2 having a weight ^average molecular weight of 7.9 × 103 in a yield of 65% by the same method as in Synthesis Example 1. This resin A2 has the following structural units.

Synthesis Example 3 [Synthesis of resin X1]
A monomer (a4-1-7) was used as a monomer, and methyl isobutyl ketone 1.5% by mass of the total amount of the monomer was added to prepare a solution. Azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the solution in an amount of 0.7 mol% and 2.1 mol%, respectively, based on the total amount of the monomers, and these were added at 75 ° C. It was heated for about 5 hours. The obtained reaction mixture was poured into a large amount of a mixed methanol / water solvent to precipitate a resin, and the resin was filtered to obtain a resin X1 having a weight ^average molecular weight of 1.8 × 104 in a yield of 77%. This resin X1 has the following structural units.

Synthesis Example 4 [Synthesis of resin X2]
The monomer (a5-1-1) and the monomer (a4-0-12) are mixed so that the molar ratio [monomer (a5-1-1): monomer (a4-0-12)] is 50:50. Then, 1.2% by mass of methyl isobutyl ketone was added to prepare a solution. Azobis (2,4-dimethylvaleronitrile) as an initiator was added to this solution in an amount of 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture is poured into a large amount of a mixed methanol / water solvent to precipitate a resin, and the resin is filtered to obtain a resin X2 (copolymer) having a weight average molecular weight of 1.0 × 10 ⁴ in a yield of 91%. I got it in. This resin X2 has the following structural units.

<Preparation of resist composition>
As shown in Table 2, each of the following components was mixed, and the obtained mixture was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

Ｂ１－Ｘ１：（特開２０１１－０８１０４４号公報の実施例に従って合成）
Ｂ１－Ｘ２：（特開２０１４－１９９３８９号公報の実施例に従って合成）

＜クエンチャー（Ｃ）＞
Ｄ１：（東京化成工業（株）製）

＜溶剤＞
プロピレングリコールモノメチルエーテルアセテート ２６５部
プロピレングリコールモノメチルエーテル ２０部
２－ヘプタノン ２０部
γ－ブチロラクトン ３．５部 <Resin>
A1, A2, X1, X2: Resin A1, Resin A2, Resin X1, Resin X2
<Acid generator>
I-2: Salt represented by the formula (I-2) I-3: Salt represented by the formula (I-3) I-13: Salt represented by the formula (I-13) I-130: Formula represented by the formula (I-13) Salt represented by (I-130) I-131: Salt represented by formula (I-131) B1-21: (Synthesized according to Examples of JP2012-224611)
B1-22: (Synthesized according to the examples of JP2012-224611A)

B1-X1: (Synthesized according to Examples of Japanese Patent Application Laid-Open No. 2011-081044)
B1-X2: (Synthesized according to the examples of JP-A-2014-199389)

<Quencher (C)>
D1: (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Solvent>
Propylene Glycol Monomethyl Ether Acetate 265 Parts Propylene Glycol Monomethyl Ether 20 Parts 2-Heptanone 20 Parts γ-Butyrolactone 3.5 Parts

<Manufacturing of resist pattern and its evaluation>
By applying an organic antireflection film composition (ARC-29; manufactured by Nissan Chemical Industries, Ltd.) to a silicon wafer and baking it at 205 ° C. for 60 seconds, organic reflection with a film thickness of 78 nm is performed on the wafer. An anti-reflective film was formed. Next, the above resist composition was applied (spin coated) on the organic antireflection film so that the film thickness after drying was 85 nm. After coating, the silicon wafer was prebaked on a direct hot plate at the temperature shown in the “PB” column of Table 2 for 60 seconds to form a composition layer. A contact hole pattern (hole pitch 90 nm) was used on a silicon wafer on which a composition layer was formed with an ArF excimer stepper for immersion exposure (XT: 1900Gi; ASML, NA = 1.35, 3/4 Anal XY polarization). / Using a mask for forming (hole diameter 55 nm), the exposure amount was changed stepwise for exposure. Ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking was performed on a hot plate at the temperature listed in the “PEB” column of Table 2 for 60 seconds. Next, the composition layer on this silicon wafer was developed using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution at 23 ° C. for 20 seconds by the dynamic dispensing method to obtain a negative resist pattern. Manufactured.

In the resist pattern obtained after development, the exposure amount having a hole diameter of 45 nm formed by using the mask was defined as the effective sensitivity.

<Mask error factor (MEF) evaluation>
In terms of effective sensitivity, a resist pattern was formed using a mask having a mask hole diameter (hole diameter of a translucent portion of the mask) of 57 nm, 56 nm, 55 nm, 54 nm, and 53 nm (hole pitch is 90 nm, respectively). The slope of the regression line when the hole diameter of the resist pattern formed (transferred) on the substrate by exposure was plotted on the vertical axis with the mask hole diameter on the horizontal axis was calculated as the MEF value.
Those with a MEF value of 4.8 or less are evaluated as having a good MEF, and are marked with ○.
Those having a MEF value of more than 4.8 were evaluated as having poor MEF and were evaluated as x.
The results are shown in Table 3. The numbers in parentheses indicate the MEF value.

The resist composition containing the salt of the present invention is suitable for microfabrication of semiconductors because a resist pattern can be produced with a good mask error factor (MEF).

Claims (8)

A salt represented by the formula (I).

[In formula (I),
X represents an oxygen atom or a sulfur atom.
Ar represents a divalent aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent.
R ¹ and R ² each independently represent a hydrogen atom, a hydroxy group, or a hydrocarbon group having 1 to 12 carbon atoms, and -CH _2- contained in the hydrocarbon group is -O- or -CO-. It may be replaced.
m and n represent 2 respectively. Two ^R1s are the same or different, and ^two R2s are the same or different.
X ¹ represents * -O-CO-, * -CO-O-, * -O-CO-O- or * -O-CH ₂ -CO-O-. * Represents the bond position with Ar.
W represents an adamantyl group, and the methylene group contained in the adamantyl group may be substituted with a carbonyl group, and the hydrogen atom contained in the adamantyl group is a halogen atom, a hydroxy group, or 1 to 12 carbon atoms. , An alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a group combining these may be substituted. ..
A ⁻ represents an anion represented by the formula (IA). ]

[In formula (IA),
Q ¹ and Q ² independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 2 to 3 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.
Y represents an adamantyl group which may have a substituent, and -CH _2- contained in the adamantyl group may be replaced with -O- or -CO-. ] The salt according to claim 1, wherein X ¹ is * -O-CO- (* represents a bonding position with Ar). The salt according to claim 1 or 2, wherein Ar is a phenylene group. A resist composition containing the salt according to any one of claims 1 to 3 and a resin having an acid unstable group. The resist composition according to claim 4, wherein the resin having an acid unstable group further contains a structural unit having a lactone ring. The resist composition according to claim 4 or 5, further comprising a salt that generates an acid having a weaker acidity than the acid generated from the acid generator. The resist composition according to any one of claims 4 to 6, further comprising a resin containing a structural unit having a fluorine atom. (1) A step of applying the resist composition according to any one of claims 4 to 7 onto a substrate.
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
(4) Step of heating the composition layer after exposure, and (5) Step of developing the composition layer after heating,
A method for manufacturing a resist pattern including.